The Underworld — Vena Asra Doll.

It was a land whose full extent humanity had yet to grasp.

A vast subterranean world beyond the reach of sunlight, and a demon continent where the most violent ecosystem in existence had flourished. The uncharted realm long known by that description now stretched endlessly before Ren.

A world without a sun.

Overhead, an eerie blood-colored mist blanketed the sky, and along the horizon, a strange aurora shimmered.

The air was raw and sticky, and with every breath came the creeping dread of something corroding the inside of his lungs.

"Watch your step, Ren. Looks like this area's a breeding ground for parasitic fungi. They scatter spores into the air, so if you breathe in, the mycelium gets into your lungs and starts eating them from the inside."

"...Wait, they actually eat your lungs!?"

Elise delivered the warning like it was common knowledge. Ren slapped a hand over his mouth in a panic.

They stood on a small rise.

At his feet, clusters of flowers bristled with thorns as sharp as blades. When he looked up, a scorpion-like insect with wings drifted lazily across his line of sight.

The sunless sky was a first, but the plants, the bugs — everything about this ecosystem was nothing like the surface.

"Elise, is it safe to touch these bugs?"

"Hmm... hard to say. The Demon Lands are crawling with creatures. They say just as many species go extinct every day as new ones are born."

Elise stroked a speckled lizard that had hopped onto her shoulder.

Whatever deadly venom or fangs the thing might be hiding, Elise herself seemed to be enjoying every second of it.

"Yeah, yeah, this brings back memories! So, what do you think, Ren? Nice place, right?"

"...'Nice' isn't the word I'd use."

"First off, the beautiful scenery."

"...You mean the blood-red sky and the ground that looks like a rotten apple?"

"The cute and lovable wildlife."

"...Those flying bugs have been trying to sting me this whole time."

"And this thrilling sense of danger!"

"That part's a solid ten out of ten, I'll give you that."

"Right?"

The dark-skinned young girl's voice bounced with delight.

"So, what about you two, Kyelse and Fear? Don't you think the Underworld's a pretty great place? It's probably been centuries since a dragon or an angel set foot here, so this must be your first time."

In response to her confident pitch—

The Dragon Princess and the Archangel answered with a sigh in perfect unison.

"Every weed here looks disgusting. I can't even work up the will to taste-test them."

"The color palette is absolutely dreadful. A crimson sky and jet-black forests. And the soil is verdigris — how ghastly. It's like a world designed by demons."

"...I mean, it literally is where demons live."

Predictable, perhaps.

As dwellers of the Valley of the Dragon and Heaven, the scenery of the Underworld clearly wasn't to their taste.

"But this really is incredible. To think places like this still exist in the world..."

Ren dug at the verdigris-colored ground with the tip of his boot. The soil had a putrid, egg-like stickiness to it — different from the sludge of the Vanessa Wetlands, but just as alien.

"Whoa!"

Without warning, the ground liquefied with a wet lurch.

Ren's boots began sinking into the earth as if being swallowed.

"Quicksand again!?"

"Nah. That's probably a burrowing beast's trap. Better pull your feet out quick, or you'll get dragged underground."

"That's terrifying!"

"People are kinda rare down here in the Underworld, you know? The bugs and beasts are probably picking up Ren's scent and swarming in."

"Hard pass on that welcome! ...And what about Kyelse and Fear-senpai?"

"I'm fine."

"Unfortunately, it seems the Underworld has taken an instant disliking to us."

The two stood unbothered on the rise.

The insects buzzing around Elise and Ren, the bizarre creatures trying to crawl up his legs — none of them came anywhere near those two. It was like someone had sprayed insecticide in a perfect circle around them.

The burrowing beast that had targeted Ren hadn't gone after them either, come to think of it.

"The beasts down here have sharp instincts," Elise said, surveying the surroundings from the hilltop.

"Fear's a hothead, so they probably figured they'd get kicked if they got too close. And Kyelse gives off a dragon's aura, so they might've been scared she'd eat them if they attacked."

"I do not kick things!"

"As if I'd eat them!"

The angel and the dragon puffed out their cheeks in protest.

They exchanged a glance.

"They're simply startled by my angelic aura. It must be unfamiliar in the Underworld."

"Same with mine as a dragon."

Three hundred years ago, the treaty between the three races had been brokered by Eleline.

That agreement included provisions against trespassing on each other's territories. Kyelse and Fear setting foot in the Underworld — however unintentional — was probably the biggest thing to happen across the entire realm in ages.

"Putting that aside, both Fear and I will behave ourselves here. Ren, there's a human scent coming from that forest. I'm guessing it's the stranded party. Shall we go?"

Kyelse pointed toward the dense jungle below the hill.

"The scent's still strong, so they couldn't have gone very deep. Want to head out?"

"Yeah, of course."

...It hadn't been long since they'd arrived, but one thing was already clear.

...The Underworld was far too brutal an environment for humans.

Nature here had evolved into something incomparably more savage than anything on the surface. He couldn't imagine a party that had stumbled in blind would last long.

"Let's go!"

Ren unwound the bandages wrapped around his spirit sword in place of a sheath and sprinted down the hill.

The Black-Leaf Sea of Trees.

A dense jungle of towering trees whose leaves grew so dark they looked dipped in ink. The aurora's glow — standing in for the absent sun — was blocked by the black canopy, leaving the interior dim and murky.

"...These are Underworld trees too?"

"Yep. Definitely a species you won't find on the surface."

Elise hopped over a thick root jutting out of the ground.

"But I'm surprised. I figured you'd jump out of your skin when you saw these trees, Ren."

"Me? Nah, it's just black leaves. The color's a bit weird, sure, but those bugs and animals back on the hill were way creepier."

"Ren, your observation skills are lacking."

A tap on his shoulder, and Fear pointed ahead.

"Those roots."

"...The roots are moving!?"

The roots twitched and convulsed, writhing like snakes — and not just one or two. Nearly every root above ground was doing it.

"Ugh, the branches move too!?"

Something had slithered against the back of his neck — a branch from the tree behind him. Thicker than Ren's arm, it had crept toward him as though it had a will of its own.

"The trees down here can move their branches and roots on their own. It gets wild when hordes of herbivorous beasts come through — the trees all start running away, and the whole forest migrates overnight."

"...And here I thought I'd finally found something normal."

He leaped over a writhing root.

"If even the trees are like this, what about the creatures living in the jungle?"

"The missing party might be in some trouble." Elise sighed from the front of their group.

"We transferred in on that open hill, remember? Standing out there draws bugs and beasts like crazy, so they probably fled into this forest. But that might not have been the best call."

"...That bad?"

"Yeah. Cutting straight through this way happens to be the shortest route to the Demon King's palace, which is why it works for us. But unless you've got a reason like that, no human should be walking through here."

Elise turned around, holding up two fingers.

"Either they get attacked by beasts, or the moving trees make them lose their bearings and they collapse from exhaustion."

"Neither of those sounds fun. Kyelse, can you still track the scent through this jungle?"

"This way. They likely fled deeper in. Shall we?"

Kyelse took point from Elise.

Beyond the parted black thickets, animal trails wound through the undergrowth. They followed those trails forward, but the whole time, the shrieks of strange birds and the roars of ferocious beasts echoed from every direction.

"...Not being able to see the beasts is the creepy part."

"I can feel their breathing very close by."

"Huh?"

"Any one of them could pounce at any moment. Look."

Kyelse pointed at the ground beyond the thicket.

There, gouged deep into the earth, was an enormous footprint. Three toes with razor-sharp claws — that much was clear, but what kind of beast had left it was anyone's guess.

"You're on dinner duty tonight, Ren. If we catch this one, we won't have to worry about meat for a while."

"That's risking our lives on a whole new level! Can't we just fish in a normal pond or something!?"

Just as he scrambled to back away from the beast's footprint—

A scream.

Not from a wild animal — unmistakably human, echoing from beyond the trees.

"That voice...!"

"Finding them is good, but the situation doesn't sound great. This way, Ren."

Kyelse crouched low, ducked under overhanging branches, and sprinted down the animal trail.

Through the gaps between the writhing trees—

"...You two!?"

An open clearing.

A middle-aged swordsman lay collapsed on the ground beside a white-haired girl crouching low. Bearing down on them was a monster of staggering size.

"A Cyclops!?"

The one-eyed giant of countless heroic tales.

Its body was covered in scales the color of ochre. Its overall shape was humanoid, but the sheer mass of its musculature defied comparison. Its appearance alone was plenty intimidating, but each of its four arms also gripped a club as thick as a tree trunk.

"Looks like they wandered into its territory. Underworld Cyclopes have curses coating their claws. Get cursed and even a demon blacks out and goes berserk — that's how potent it is."

"A body that huge and it's got curses on top of it!?"

Ren tightened his grip on Spirit Sword Vierge.

The Cyclops raised its club to crush the two fallen victims, then swung it down. In that split-second gap between the upswing and the downswing, Ren dashed beneath the giant's legs.

"H-Hey, what the hell are you doing!? You're just gonna be more food for this thing!"

Ignoring the fallen swordsman's warning, he raised the gleaming spirit sword.

The massive club came thundering down with a howl. He focused on nothing but its tip, and swung without an ounce of hesitation.

Sword met club.

The Cyclops flinched. The blade of Spirit Sword Vierge had sliced clean through the club mid-swing, just as it was about to crash down on the pair.

But that alone wasn't enough to stop the giant.

Watch out! Watch out!

Gnome materialized on his shoulder, and Ren threw himself aside.

"Four arms — figures it'd have a quad-wielding style..."

The Cyclops still had three clubs left.

The instant it realized Ren had severed one, it launched a simultaneous attack with the remaining three. If he'd pressed the attack instead of retreating, he would've taken hits from three directions at once.

"...Gnome... a spirit bonded with a human? No way..."

The white-haired girl murmured in a daze.

Behind Ren, meanwhile—

"Looks like an adult versus a child. Or maybe a kitten versus a lion?"

"Well, he'll manage somehow. Ren, I can mend compound fractures in a heartbeat, so feel free to fight as many times as you need. Think of it as gaining experience."

"I can break curses too, so go ahead and get cursed as many times as you want, okay?"

The Three Princesses lounged on a tree root. But Ren had no room to respond to their leisurely commentary — he gripped the spirit sword and kicked off the ground with everything he had.

He circled to the Cyclops's flank, swinging wide to the right.

The giant turned to track him, and he used that momentum to reverse into a leap, rattling its line of sight. In the instant its gaze wavered, he cut hard to the left and slipped behind it in one burst.

...Don't get trampled.

...But stay as close as possible!

The creature's single eye — its defining feature — couldn't track what was directly behind it. But the Cyclops sensed the presence at its back and whipped around.

"Salamander!"

Light fire?

"Yeah."

The translucent blue blade drank in Salamander's power and blazed into a crimson sword. Its edge sliced through the Cyclops's club like paper, then carved through the giant's hardened hide.

"It's not over yet, Ren."

"I know!"

The Cyclops retreated with frightening agility. The spirit sword had barely grazed its inner thigh. A scratch that shallow probably didn't even register as pain.

...Living up to its legend.

...The tales of veteran knights struggling against this thing weren't exaggerating.

He dropped into a crouch, the blazing sword at the ready.

The enraged Cyclops was about to counterattack — he could feel it. Ren braced for the clash—

But instead—

The giant's clubs thudded to the ground, one after another. It dropped its weapons, and the monster turned and charged into the forest with footsteps that shook the earth.

"Huh? It... ran away?"

"Oh wow. Maybe it got spooked when your sword suddenly caught fire?"

Elise sat on a tree root like it was a chair.

"The flames triggered its flight instinct, maybe?"

"Was it scared of fire?"

"Hmm. If anything scared it, it's probably not fire specifically — more like demonic spellcraft in general. Like, there's this mountain of Hellfire in the Underworld, and about four hundred years ago, Achendia the Demon General of Blaze got furious and torched it. It's still hot to this day, so even the beasts won't go near it. Plenty of them are wary of demonic spellcraft."

"...So your fire might've been mistaken for a demon's spell."

He let out a wry laugh and glanced at Salamander.

"Thanks. Looks like the coast is clear."

All done?

The crimson fire-lizard looked almost disappointed.

Once the flames wreathing the spirit sword died out—

"Whooooa, that was incredible! You're amazing, kid!"

"Whoa—!?"

Before he could even turn around, someone tackled him from behind in a bear hug.

It was the middle-aged swordsman who'd been on the ground when the Cyclops attacked. He was taller than Ren, so "bear hug" was generous — it was more like a full-on headlock.

"You drove that monster off, just like that! You're one hell of a fighter for a young guy!"

"G-Glad you're okay, but... I'd really appreciate it if you let go..."

"Hm? Right, right. Ha ha ha! Sorry about that, kid. When I get caught up in the moment, my body just moves — it's a bad habit of mine."

The man released him with booming laughter.

Tanned skin, muscular build. Late thirties, maybe pushing forty. More than old enough to be considered a seasoned veteran — both as a swordsman and as a party member.

"Name's Dan, by the way. Forgot to introduce myself. I run a party called Venus Light, and the family calls me Boss. Pleased to meet you."

"Family?"

"Yeah. The members of my party are like little brothers and sisters to me. Calling them just 'members' feels too cold, you know?"

"...That's a pretty unusual way to put it. And that's a seriously cool party name."

"Right? A man's gotta look sharp, starting with the name."

Dan puffed out his chest with pride.

"So what about you, kid?"

"...Ren."

"Ren, huh. But hey, kid — now that I'm looking, you remind me of someone."

Dan squinted at him.

"Have you been making a name for yourself somewhere lately? I've been hearing rumors — word on the wind about someone who looks like Eleline stirring things up all over the place."

"Ah. That's probably me and those three behind me."

He glanced back at the Three Princesses, who'd been watching from the sidelines.

"...But we haven't really done anything that impressive."

"Oh, so you're that party everyone's been talking about! Well, well. What a stroke of luck — running into you in a place like this."

Dan's expression softened with visible relief.

"It's been one surprise after another, though. I'd heard the Vanessa Wetlands were dangerous, but I never expected Cyclopes. We pushed in a little too deep and the scenery completely changed — got chased by beasts I'd never seen before, and we were at our wits' end. ...Anyway, not to pry, but what brings your group out here?"

"Your companions asked us for help," Fear answered.

"To add to that, this is the Underworld. It's not the surface you know," Kyelse said.

"There was a Gate at the Vanessa Wetlands. You probably didn't notice, but that's where you and your party transferred from into the Underworld," Elise explained.

The three girls laid it out one after another.

"...What? The Underworld?"

Dan looked around.

The strange insects and creatures found nowhere on the surface. The putrid-colored earth. The black-leafed, self-mobile trees. He scrutinized every last detail, and then—

"The Underworld!? W-W-W-What the hell — this is a disaster!"

He screamed and fell over.

"Hey, Misty, you didn't notice either, right? You just thought this was a weird forest, right?"

"I noticed."

"Then why the hell didn't you say something!?"

"I wanted to, but we were being chased by a Cyclops the whole time."

The white-haired girl brushed the dust off her dress.

Clearly a member of Venus Light, same as Dan. But—

...Huh?

...What is it about this girl?

Hair as white and luminous as freshly fallen snow. Skin so pale every trace of pigment seemed to have drained away.

She was about Kyelse's height, but her frame was so slender it felt wrong to even call it delicate. Her expression was muted, and she didn't say much.

The kind of girl you'd walk right past on any street without a second glance — her presence was that faint.

And yet—

...My chest feels... restless?

...Why? I've never met her before.

Just as a strange, floating unease crept over him — like the nagging feeling of having forgotten something important—

"Is something the matter?"

Their eyes met.

Misty addressed him in a flat, inflectionless voice.

"Is there something about me?"

"N-No! Sorry for staring. It's nothing, really!"

"I see."

The white-haired girl turned away. But—

"'Is something the matter' — really, Misty?"

"Eek!"

"The guy just saved our hides, you know? The least you could do is say thanks. That's how you build connections between people. Am I right?"

"...Boss, please don't run your dirt-caked fingers through my hair."

Dan ruffled Misty's hair with mud-stained hands, and she accepted it with a look of quiet resignation.

Like a parent and child. The heated affection of an overzealous father, endured by a precocious kid who'd long since accepted that this was just how parents were.

"Come on, give the man a proper bow, Misty."

"...Thank you."

"Ha ha ha! She's not exactly warm and fuzzy, but deep down she's a good kid with a big heart — cut her some slack. Anyway, we've got Rin and Silk waiting for us. Gotta get back to the surface ASAP."

"You can't."

"Huh?"

Elise's casual one-liner made the veteran swordsman blink.

"The Gate at the Vanessa Wetlands is broken. We tried too, but the one on the hill here won't activate anymore. Meaning you can't get back to the surface."

"...So that means?"

"You'll be living in the Underworld for the rest of your life. Good luck!"

"AAAAAAAAHHHH!?"

"Now, now, Elise — that's not nice, scaring him like that."

Fear stepped in to scold the grinning former Demon King, while Dan's scream still echoed.

"He actually believed every word."

"Because it's funny. I don't mind humans who give me a good reaction."

The former Demon King pressed a hand to her stomach, barely holding in her laughter.

"Relax. I'll let you use the Gate at the Demon King's palace as a thank-you for the laughs. It's been centuries since a human got to use that one."

"...The Demon King's palace...?"

"That's our destination. She's saying we should all head there together," Fear said.

The Demon King's palace.

It was the lair of the Underworld's demons and the stronghold of their ruler, the Demon King — famous enough that everyone had heard of it. But what the place actually looked like was something even Ren hadn't been told yet.

...And the Five Great Disasters are there too.

...Even I'm worried about whether we'll actually make it back in one piece.

Elise insisted "You'll be fine with me around," but if Ren was being honest, it felt like voluntarily walking into a cage full of apex predators.

"By the way, Ren. Keep your sword out."

Kyelse was the last to rise from the tree root.

Her refined features sharpened as she glared into the thicket.

"Something with cold breath is approaching. Nine times out of ten, it's a beast."

"Heading our way!?"

Beasts — the blanket term for creatures that radiated the same Demonic Aura as demons. Some species could even wield spellcraft. All of them were cunning, deeply wary, and savage. In the Underworld, they were arguably a greater threat to a party than the demons themselves.

"It's making a straight line for us. Hmm, this might be a nuisance."

"A nuisance — like, Cyclops-level?"

"Not even close."

The words barely left Kyelse's lips when—

The jungle fell silent.

The growls and snarls that had filled the air moments ago cut off as if drowned.

"...This pressure—!?"

The instant he felt the wave of cold Demonic Aura blast through the thicket, every inch of his skin broke out in goosebumps. Sweat erupted down his back. His heartbeat spiked.

"What is that!?"

Trees toppled and splintered as the beast crashed through into view.

It was an enormous jet-black hound.

Standing on its hind legs, its forelegs could have reached the second floor of a house. Its entire body was sheathed in overdeveloped muscle, and its dark fur had hardened to an armor-like shell.

And its most defining feature — three heads, rising from a single neck.

"C-C-C-Cerberus!?"

Dan's teeth chattered so hard he couldn't get the word out.

This was a seasoned swordsman who'd faced countless Roaming Beasts across countless journeys — and one look at this creature shattered his fighting spirit completely.

The gatekeeper of the Underworld.

A hound whose ferocity, once roused, sent even high-ranking demons fleeing. A true representative of the Underworld's beasts.

...So that's why the Cyclops ran. It wasn't afraid of fire.

...It sensed this thing approaching.

Without even a moment to wipe the sweat dripping down his face, Ren stared up at the colossal hound with the resolve of a man facing his end—

...Buy time for Dan and Misty to escape.

Just as that split-second calculation ran through his mind—

"Oh! It's the Cerberus!"

Elise leaped onto the beast's leg.

"So you sensed your master coming home and came to greet me? Huh? Did you?"

"Silence."

Cerberus swatted Elise aside with one foreleg.

"Ow! Hey, quit it!"

"You... you finally return to the Underworld, and..."

Three heads moved independently.

One kept its gaze fixed on Elise.

The second tracked the Dragon Princess and the Archangel. The third looked down at Ren, Dan, and Misty.

"A dragon and an angel? You've dragged quite the nuisances into the Underworld. The stench of Heaven and dragon reached all the way to my den..."

"Ah, so that's what got your attention?"

"Answer me!"

"Circumstances," Kyelse said, stepping forward in Elise's place.

She met the fuming beast's gaze head-on.

"If our presence offends you, I apologize. Were the situation reversed and you had trespassed into the Valley of the Dragon, I would be angry too. We're headed for the Demon King's palace. We have no intention of causing trouble in the Underworld."

"You have our word. We'll return to the surface as soon as our business is done," Fear added.

Cerberus looked back and forth between the two of them and Elise, then ground its teeth with a displeased rumble.

"Then leave quickly. I'm going back to my den."

"Oh, hold on! You're fast on your feet. Give us a ride to the palace."

"What...?"

"Your den's on the way — it won't even be a detour."

It was Elise who called out to her familiar once more.

"What sort of nonsense—"

"Want some Argines bones? Your favorite treat — I bet there's a big stash left in the palace storeroom."

"...No."

"Fine, I'll go big. Two."

"Three."

A deep, resonant growl rolled through the air.

"Do you grasp how many heads I have?"

"Yeah, yeah. It's a deal, then. Oh, but I'm gonna walk with Ren and show him around the Underworld, so I'm good. Give these two a lift to the front of the palace."

"...Huh?"

Dan's face went rigid when Elise pointed at him.

"W-Wait, wait, wait! What's gonna happen to—"

"This."

The beast's tail coiled like a serpent and snatched up the two members of Venus Light.

"I'll dump them in front of the palace."

"AAAAAAAAAHHHHHHHH!?"

Cerberus tore through the trees and vanished in an instant. In the time it took Ren to draw a single breath, the jet-black colossus had already disappeared into the distant forest.

"Is that... going to be okay?"

"Better than walking through the Underworld with us, right? Forget Ren — for ordinary humans, wandering around the Underworld is just reckless."

Elise started walking, tracing the Cerberus's trail of footprints.

"Alright, back on track! Now then, what beast will we run into next? There's still plenty more, so look forward to it, Ren!"

"...Let's keep it reasonable, please."

Spirit sword in his right hand, Ren chased after Elise.

"You guys are so slow!"

"...I never expected we'd be stuck waiting outside the estate for a full day and night."

Atop a hill surrounded on three sides by sheer cliffs.

Dan and Misty, exhausted and slumped on the ground, sprang to their feet the moment they spotted the group.

"Hm? Hey, kid, you're looking pretty beat up."

"Yeah... well, I spent the entire day and night wandering through the Underworld."

They'd been told it was a three-day walk from the Black-Leaf Sea of Trees to the Demon King's Palace at a leisurely pace, so Ren had spent the whole day running in a desperate bid to get there as fast as possible.

"I got chased by a demon beast and ran right into a nest of royal poison insects... Tried to escape by diving into a lake, but there was this huge man-eating fish in the water... Swam for my life to the far shore, and then I ended up lost in some desert where the magnetic field was all messed up..."

"...Wow. Glad you made it in one piece."

Dan's face went serious.

"But damn, the Demon King's estate really does exist, huh."

A grand mansion veiled in white fog.

A clock tower rose from the central roof, its warped dial slowly ticking away the hours. A vast garden stretched out before it, its manicured lawn punctuated by flower beds bursting with vivid, oversized blooms, while black-winged fairies flitted about above them.

The splendor of a royal estate, married to an otherworldly dreamlike beauty.

Two entirely different aesthetics, harmonized into one seamless design.

"Pretty, right? The ones living here now are the Five Great Disasters and their subordinates, plus a whole bunch of others. Basically, everyone's welcome — the more the merrier. So come on in, Ren! Let's go, let's go!"

"H-hey, Elise!?"

She pushed him forward, and before he knew it they were jogging up to the palace doors.

A pair of double doors gleaming in a dull bronze. True to form for a demon's estate — the entire surface was laced with some kind of spell, wrapped in a faint, ominous purple-violet glow.

"...I'm supposed to open this? This door? It looks like one wrong touch and a trap goes off."

"Nothing ventured, nothing gained."

"In the Underworld, we're merely along for the ride."

Watched over by a carefree Kyelse and Fear, with Dan and Misty's anxious stares boring into his back, Ren reached for the doors of the Demon King's Palace.

A screech of metal grinding against metal.

Before his fingertips even made contact, the doors began to move on their own.

They swung inward.

Beyond them lay a lavish lobby, illuminated by the dazzling light of a chandelier.

"Welcome home, Lady Elise.

And welcome, everyone, to the Demon King's Palace — Rieselschat."

A girl in a housekeeper's uniform bowed deeply.

Having only a single person to greet them in this enormous palace felt a bit lonely, but the girl herself showed no sign of minding. If anything, she carried herself with a solemn dignity that suggested she took pride in being the sole one here.

I am the only one — and that is precisely why I devote everything I have.

That was the impression she gave.

"Pardon my late introduction. My name is Lulu, and I serve as the head housekeeper of this palace."

An elegant dress paired with a white hair ornament.

A blue-haired demon dressed in exactly the same working attire as a human housekeeper. Her composed bearing and polished speech. Neat and refined, yet with an air of nobility about her features.

The one thing that marked her unmistakably as a demon was her eyes — irises that blazed a vivid, brilliant red.

Red full moons.

Eyes of such depth they seemed ready to pull you in. A bewitching, demonic gaze.

"Today, for all of you, I've prepared— oh, Lady Elise?"

"Lulu!"

Before the head housekeeper could finish, Elise had already thrown herself at her in a flying hug.

"It's been forever! Hey hey, how've you been?"

"Quite well, thank you. You must be exhausted from your long journey, Lady Elise. Your room is all prepared, so please take it easy today. But of course, before that — don't forget to pay your respects to the Demon King."

"Ehhh... Do I really have to go see him right away?"

"I'm afraid so. It's been tradition in the Demon King's Palace since time immemorial. Even you would be upset if a demon forgot to pay their respects when you were Demon King, wouldn't you, Lady Elise?"

Lulu smiled, amused.

"The Demon King has been nervously awai— I mean, eagerly awaiting your return."

"That's great and all, but listen, Lulu—"

"This is about bringing a dragon and an angel into the Underworld, isn't it?"

The head housekeeper gently set the clinging Elise down onto the carpet and gave a resigned half-smile with a shrug.

"I heard from Cerberus. The three-hundred-year pact notwithstanding, they do have a complicated history with us... Still, if you've brought them here, Lady Elise, then they are our guests. I've already notified the estate's familiars and the Five Great Disasters. I made it very clear — no brawling under any circumstances."

"That's our Lulu!"

"You flatter me. And—"

The girl's vivid red eyes settled on Ren, standing in front of Kyelse and Fear.

A silent appraisal.

She studied him from head to toe, taking her time. Then:

"I see. The resemblance truly is remarkable."

The demon head housekeeper's expression softened.

"You must be Master Ren."

"...You know who I am?"

"Achendia told us. A human who bears the Sword Emperor Eleline's spitting image — and who commands spirits, no less. The Demon King, the Five Great Disasters, everyone in the estate has been looking forward to seeing you for themselves."

She gave Elise's head a quick pat, then turned on her heel — the blue-haired girl in one smooth motion.

"Everyone, I'll now guide you to the Demon King's audience chamber. Please follow me."

"Come on, everyone. Oh, and you two from Venus Light, you're coming too."

Elise walked off hand in hand with Lulu. Behind them came Ren, then Kyelse and Fear, and finally the two members of Venus Light bringing up the rear.

"I'll give you a tour of the palace as we walk."

Their hard-soled footsteps echoed through the corridor. The head housekeeper moved down the marble floor — polished smooth as glass — and, without breaking stride, pointed ahead.

A four-way intersection lay ahead.

Did the corridor have no end?

No matter how hard Ren squinted, the passage stretched on and on until it blurred into the distance.

"It's not an illusion. The estate is simply that vast. If you were to run from one end of this corridor to the other, a human would collapse from hunger before reaching the far side."

"...Th-that big!?"

"Yes. You may have noticed the fog around the palace when you saw it from outside — that's a high-level spatial interference spell. The thinking was that an excessively imposing exterior would be an eyesore, so spatial compression was applied. That's why it only appears to be that size from the outside."

Lulu stopped at the four-way intersection.

Ren picked up on what she was silently showing them, and exchanged a glance with Dan at the back of the group.

"Hey, kid — is it just me, or what's going on with this maze?"

"I was thinking the same thing."

The corridors branching left and right from the intersection led to more intersections. Beyond those, the passages forked again into Y-shaped splits that stretched on without end.

...This isn't just an estate.

...This is a labyrinth built by demons.

"I trust you can imagine the scale now."

Lulu turned right at the intersection.

"The estate is so vast that you haven't seen any demons or familiars yet, but the Demon King's Palace is actually quite a bustling household. There are seven hundred and sixty-five demons and familiars combined, plus four thousand two hundred and ninety-one black fairies tasked with cleaning and patrolling the palace."

"And about eighty demon beasts roaming the gardens and courtyards, right?"

"You remember well, Lady Elise. Eighty-four, to be exact."

The head housekeeper rattled off the numbers without hesitation.

"My, that sounds like quite the management challenge," Fear sighed in admiration.

She twirled a strand of her brilliant golden hair around one finger.

"I can't even remember how many of my fellow angels there are in Heaven. Isn't that right, Kyelse?"

"You're telling me. Baby dragons are always wandering off in the Valley of the Dragon and causing a panic. Every time, Calra has to fly all over the valley searching for them."

Kyelse folded her arms and shook her head.

"You don't know how many students and teachers are at Holy Fiora Journey Academy either, do you, Ren?"

"Huh? Oh, now that you mention it..."

Despite being enrolled for three years, there were plenty of teachers whose names and faces he couldn't match up.

As for students, he could manage his own class, but the total number per grade — let alone every individual name — was more than he'd ever cared to memorize.

But Lulu, this demon, probably had all of it committed to memory.

The sprawling layout of the entire palace. Every single demon, fairy, and beast — their identities and names, all perfectly catalogued.

"Being a head housekeeper is amazing..."

"I've been at this for a long time. At this point, it's half hobby."

The demon in housekeeper's attire answered as though it were the most natural thing in the world.

"We'll be walking a bit more. The corridors may start to look the same, but the landscape paintings and vases on the walls are all different. They serve as landmarks when navigating the palace, so please take note as we walk. However—"

"Hey, would you look at that. Classy stuff. I happen to know a thing or two about fine crafts."

Before Lulu could finish her warning, Dan had already spotted a vase further down the wall and drifted toward it.

"Hey, Misty, check it out. There's even a flower basket."

"...A flower basket?"

"It's a bamboo vase. You cut bamboo and weave it in tiers. Looks nice and cool, so it pairs great with blue and white flowers. And these blue flowers — for the Underworld, they're actually pretty, don't you think?"

The middle-aged swordsman approached the vase with an appreciative nod, thoroughly impressed.

"Huh? But there's no scent from the flowers... Wait— WHOOOOAAAA!?"

The flower arrangement suddenly ballooned in size and lunged at him as a monstrous plant creature.

"However, please exercise caution when admiring the artwork and furnishings. Nine out of ten are booby-trapped."

"You little — that's practically all of them! M-Misty, help!"

"...Hang in there, boss."

The white-haired girl hauled on Dan as vines pinned him down. While Ren pitched in to help with the life-or-death rescue operation:

"Um, Lulu?"

"Just Lulu is fine."

"Is this whole estate like this? Traps everywhere?"

"A hobby of the first Demon King. These corridors, too — one wrong turn and you're trapped in an infinite loop. Even Lady Elise can't count how many times she's gotten lost here. Isn't that right, Lady Elise?"

"Ahhh, memories."

"A Demon King who gets lost in her own palace... That's bad."

Ren tried to memorize the paintings as landmarks while walking, but there were so many similar landscapes that he gave up almost immediately.

...Apparently, complex underground labyrinths require a skilled cartographer to accompany you.

...That's basically what this is.

"You don't have to walk so nervously, Ren. This is my home, you know."

"It's your home — that's why I'm nervous!"

He stuck close behind Lulu and Elise as they walked hand in hand.

"Hm?"

The air around them shifted without warning. The chandelier's gleam, the paintings and furnishings — nothing had physically changed, and yet the air felt heavy.

Suffocating... like being plunged into the deep sea where no light reached.

"Noticed, did you, Ren?"

"We've entered an area thick with Demonic Aura. There must be an extremely powerful demon nearby."

Fear and Kyelse remarked matter-of-factly.

But even those two had the faintest edge of wariness in their expressions.

"This is the Five Great Disasters' private territory."

Elise, walking at the front, turned back.

"The Demon King owns the palace, but this area is the exception. It's been specially carved out as the Five Great Disasters' own domain."

"So all of the Five Great Disasters are here?"

"Yes. Though they're a capricious bunch. One might hole up in their room for years, only to leave the estate and not come back for a century. If they'd just say something before heading out, I wouldn't need to prepare their meals..."

The head housekeeper pressed her fingers to her brow and sighed.

"Past the Five Great Disasters' chambers is the Demon King's audience hall. This way, please."

The demon girl walked briskly ahead.

In terms of raw power, the Five Great Disasters surpassed even the current Demon King — the strongest fighting force in the Underworld. Given they'd been granted their own private territory, their status was likely on par with the Demon King.

And yet, Lulu walked through their domain with nothing but poise, carrying all the authority befitting a head housekeeper.

...She doesn't seem particularly intimidated.

...Is the head housekeeper position actually a pretty high rank in the Demon King's Palace?

The thought flickered through his mind—

"Huh?... Whoa!"

Impact.

The jolt hit his whole body. His legs buckled, and Ren caught himself against the corridor wall.

He'd been distracted at a corner, and someone rounding it from the other side had walked right into him.

"Ow... S-sorry—"

"...N-no, my apologies. Are you one of the guests here to see the Demon King? Forgive me."

The other person bowed low, unsteady on their feet.

Standing before him was a demon about the same height as Ren.

In human terms, they looked to be in their late teens.

Dark green hair fell to shoulder-length, framing eyes tinged with red. The face was strangely androgynous — from one angle it looked delicate and pretty, from another it could pass for sharp and handsome.

By contrast, the armor they wore was fierce — spiked full plate.

"......"

"......"

Ren stared at the demon.

The demon blinked a few times, rubbed their eyes, and stared right back—

"Ahh—!?"

Ren and Mia pointed at each other and shouted at the same time.

Mia, the Demon General of Wave.

One of the Five Great Disasters, and the world's only Bastard — a hybrid born of dragon and demon blood.

She possessed an unparalleled regenerative ability that healed any wound almost instantly, and her body adapted to develop resistance against any attack she'd already taken.

There was no way to beat her.

When Ren and Elise had been forced into a duel with her in the Holy Land Canaan, they'd given up on defeating her outright and resorted to a last-ditch gambit — forcibly teleporting her into the Underworld.

"Found you — I found you, Ren! I never thought I'd run into you in a place like this!"

Mia cried out, her face alight with excitement.

"That quick thinking at the Holy Land was impressive... But this is the Underworld. You can't pull the same trick here. Now — it's time for our rematch!"

"Huh? Hold on, just like that!?"

"No more talk!"

Mia drew back her fist to swing.

But then—

"That's enough."

A single command from the blue-haired girl behind him stopped the Demon General of Wave in her tracks.

"Please don't interrupt my tour. I'm in the middle of escorting Master Ren."

"...What?"

The brown-skinned demon whirled around, menace bleeding into her voice.

"Lulu, do you know who you're speaking to?"

"Do you intend to raise a hand against a guest of the Demon King?"

The head housekeeper stood her ground, unflinching, even under the glare of one of the Five Great Disasters.

"What's more, you've already lost to him once. If you want a rematch, you should conduct yourself accordingly. Lashing out with words and fists will never lead you to true strength."

"...What did you say?"

"And frankly, Mia—"

Lulu let out a deliberate, theatrical sigh and folded her arms.

"You just want someone to hang out with, don't you?"

"

!?"

Mia's brown cheeks flushed crimson in an instant.

"Th-that's not it! I just... I just happen to like solitude! Fraternizing is beneath me. I won't stand for these baseless—"

"Enough. Put your fists away. Look — Lady Elise is watching."

"......Fine."

Thoroughly deflated, the brown-skinned great demon turned away. She slumped off down the corridor, shoulders drooping. Watching that lonely retreating figure:

"Mia is the odd one out of the Demon King's Palace," Lulu said with a shrug.

"The world's only Bastard — a hybrid of dragon and demon. Even though she was born in the Underworld through a Forbidden Spell, even though she carries demon blood, the dragon blood in her prevents her from truly fitting in with her fellow demons. She doesn't have the full trust of her subordinates, either. It's been hard on her."

"...Sounds like the same kind of thing happens everywhere."

Discrimination based on lineage existed even among demons. The treatment he'd received at Holy Fiora Journey Academy came to mind, and Ren scratched the back of his head.

"Dealing with her again isn't exactly appealing, but if that's the situation—"

"I'll keep her company."

"...You, Kyelse?"

"Given her situation, I can hardly look the other way."

The Dragon Princess pointed in the direction Mia had gone.

"She may be an exception, but if she carries dragon blood, then she's kin. Leave it to me. I'll cheer her up and be right back."

"I don't mind, but won't you get lost?"

"I'll be fine. I can follow scent trails, or just ask Mia for directions. There's no shortage of ways to regroup."

Kyelse jogged off after Mia.

Watching her go, Elise and Lulu exchanged a look.

"Is that all right, Lulu?"

"Yes. Now then—"

Just as Lulu was about to take a step forward, she sensed it. Another presence — footsteps coming from the opposite direction this time.

More than one.

"Busy, busy, busy. Hey, Beldred, do you remember where the flower-viewing spot is?"

"Mi'i and her subordinates should have gone ahead. She said the area's in the demon beasts' territory, so we need to get there quickly and help tame them."

Two demons hurried across the corridor directly in front of them.

One was a large demon fused with black-gold armor.

The other was a blonde demon in a long skirt. She looked like a human girl, except for the long rabbit-like ears protruding from her head and a fox-shaped tail peeking from beneath her skirt.

"Oh my, those demons."

Fear turned back with a meaningful little smile.

"You know them, Fear?"

"Indeed. We've exchanged blows."

What did that mean? Before Ren could wonder further, more footsteps echoed from deeper in the corridor.

"Nyaaah! M-m-master, I brought the sake from the warehouse like you said!"

"Oh, Meris, what a fine selection. As expected of my familiar."

"B-but this is from the Demon King's private stash! If we empty it, we're gonna get in trouble..."

"Just fill it with water afterward and no one will notice. Now then, Meris, carry the barrel along. Don't jostle it too much — it'll ruin the flavor."

"It's h-heavy..."

The one hauling a sake barrel bigger than herself was a red-haired girl in a black dress. She was apparently in such a rush that she bolted past without sparing them a glance.

And sauntering along behind her:

"Oh, Lady Elise? And Ren, it's been a while! How've you been?"

"Achendia!?"

Golden eyes like a leopardess's, with flowing crimson hair — a bewitching demon of stunning beauty.

Achendia, the Demon General of Blaze — a legendary great demon whose exploits were known even in the human world — had casually popped out from the corridor ahead.

"Hellfire that will burn the world to ash. Let me teach you what true sorcery is."

The battle at Galia Flame Mountain.

His first battle to the death, his first fight against a demon — the pain of those flames was still seared deep in his body.

"Oh, come on. Don't look so tense."

Achendia traced a fingertip along her glossy lips and flashed a sly grin.

"Elise and Lulu are with you, after all. You're here for an audience with the Demon King today, right? I wouldn't dream of messing with a guest."

"...Can I trust that?"

"Of course. I've got flower-viewing plans today, myself. Meris, carry the sake for me, would you?"

"Y-yes ma'am!"

Her familiar dashed off down the corridor, barrel in arms.

"Hmm. But you know, Ren, you've gotten a pretty sharp look about you."

The great demon leaned in close to study his face.

"Wh-what...?"

"Ahaha, adorable. Hey, Ren, want to come flower-viewing with me? Lulu, can I borrow him? I'm dying to hear about his adventures."

"No."

"Stiff as ever."

Achendia puffed out her cheeks in an exaggerated pout.

"But what a shame. The Konohasakuya is having its once-in-two-hundred-years wild bloom right now. The entire Underworld sky blanketed in cherry blossoms — an absolutely breathtaking sight. And we've got plenty of delicious sake."

"Then I'll join you."

"Fear!?"

"Now, now, Ren. Consider it a learning opportunity."

"...Learning?"

"Indeed. It's not every day an angel sets foot in the Underworld. As a servant of Goddess Resflaze, it is my duty to conduct a reconnaissance of the Underworld."

Fear's expression was uncharacteristically dead serious.

"Is that true?"

"Absolutely. Look into my serious eyes."

"...And the real reason?"

"I want to drink."

"You couldn't even hold out for two seconds!?"

He'd half expected as much.

The instant Fear had seen the sake barrel Achendia's familiar was carrying, her eyes had gone full predator — the gaze of a carnivore locking onto prey.

"Then it's settled. Lady Elise, I'll be borrowing your companion."

"I'll be back after just a drink or two."

With a parting wink, the Archangel strolled off alongside Achendia. Their figures eventually dissolved into the haze until they disappeared from sight.

"Hey, Elise, is this okay?"

"...Hmm."

Elise stared up at the ceiling in silence, brow furrowed, clearly turning something over in her mind. Then, abruptly, she let go of Lulu's hand and raised her voice.

"No faaair! Kyelse and Fear get to go have fun while I'm stuck here? I haven't been back to the palace in forever and I want to explore! Who cares about seeing my little brother? I'm not even happy about it. Anyway — Ren, you've got this! Good luck!"

"Wha—!? Wait, Elise, all three of you disappearing is a bit—"

"Lulu's here, you'll be fine."

"Hey, get back here!"

He reached for her, but it was already too late.

She slipped out of his grasp in an instant and sprinted back down the way they'd come.

The only one left from the party was Ren himself. The rest of his escort consisted of Lulu, the head housekeeper he'd just met, and Dan and Misty from Venus Light.

"Whoa, kid. Is it really okay? Your girls just got lured off by demons."

"Those two will be fine, probably. It's us I'm worried about..."

Kyelse and Fear could handle themselves even in the heart of demon territory. The ones who should be concerned were the ones left behind.

...Achendia said she wouldn't attack us, but...

...I have no idea what the rest of the Five Great Disasters, or the Demon King, or the other demons are like.

At Galia Flame Mountain, Achendia's subordinates had attacked them one after another. At the Holy Land Canaan, Mia had launched a one-sided assault. Among the higher beings — dragons, angels, and demons — demons were unquestionably the most belligerent.

"It was to keep the demons in check."

"Huh?"

"Those three must care about you quite a bit."

The head housekeeper allowed herself an amused smile.

"Don't you see? Kyelse went after Mia, and Fear went with Achendia — the two demons you've already fought. And Lady Elise headed off to make sure the remaining Demon Generals and their subordinates don't clash with those two."

"...All three of them?"

"Yes. Of course, your concern about the current situation is justified, Master Ren. A belligerent demon like Mia could very well decide to attack you on a whim, just for a test of strength. That said—"

Lulu lifted the edge of her long skirt and curtsied once more.

"Please rest assured. Lady Elise entrusted you to my care, and I have no intention of betraying that trust. Even the Five Great Disasters will not lay a finger on you."

"...The remaining three great demons, then."

"Two."

"Wait, two? But there's Achendia, and Mia, and then..."

He counted on his fingers.

The numbers didn't add up. He hesitated over whether to ask Lulu about it, but the moment passed.

"So the Demon King is up ahead."

It was probably the first time she'd spoken up. The white-haired girl, standing at the very back of the group, finally broke her silence.

"Boss. It's the Demon King next. I'm sure it'll be terrifying. What should we do?"

"What do you mean, 'what should we do'? D-don't you worry! I'm right here! Demon King or whatever, one hit from my fist of justice and it's over!"

"Your legs are shaking."

"Sh-shut up! You just wanted to say that, didn't you!?"

Dan shook his fist at her in mock anger, and Misty scurried away.

Whether they were scared or relaxed was anyone's guess. The head housekeeper watched their exchange from the corner of her eye, then set off down the corridor once more.

"You've brought quite an interesting party with you, Master Ren."

"...Y-you think?"

"Indeed. I haven't reported those two to the Demon King yet, but we may as well mention them during the audience. We're almost there."

A thin black mist drifted through the void.

The light pouring down from the dazzling chandelier was blocked by the dark fog, leaving the room perpetually dim and filled with a faint chill that crept across the skin.

The hall was a vast rectangle, large enough to hold a foot race.

A thick carpet ran down the center of the vertically oriented room, stretching straight toward the far end as if beckoning visitors onward.

"This is the Demon King's Palace, Rieselschat — the 'Lid of Subjugation.'"

Lulu stopped midway through the hall.

"Thank you for waiting, Demon King. I've brought the guests from the surface."

"......"

As Ren and the others stared upward, scarcely remembering to breathe, the figure seated on the throne slowly moved.

—A demon.

A body of dark hues, as if every pocket of darkness in the world had converged into one.

Hard armor encased every inch of its frame from head to toe, and two pairs of horns — one long, one short — jutted from its skull.

Then there was the massive jet-black tail that spilled over the edges of the throne, and those cold white eyes.

Truly...

The demon on the throne was the very embodiment of what any human would picture when they heard the word "demon."

"Holy craaap!! That's the real freakin' Demon King!?"

Dan stumbled backward, his voice cracking.

"I-I ain't scared!? L-l-leave it to me, Misty. No matter how terrifying the guy is, I'll protect my family... protect... c-can I protect them!?"

"Your legs are shaking."

"I'm doin' my best here!"

Dan forced himself to speak up, planting himself as a shield in front of the white-haired girl.

"...Quite the lively human."

The demon on the throne said this, chin propped in one hand.

The voice echoed as a deep bass rumble. Its vocal apparatus was probably structured differently from a human's. The way the sound resonated was closer to the vibration of an insect's wings.

"Demon King, the one I truly wished to present is right here."

Lulu's outstretched hand touched Ren's back.

"Go ahead, Ren."

"Uh... I'm supposed to walk up there?"

"Yes. Please proceed to the throne. I'll be waiting right here."

Nudged forward, Ren took small, halting steps.

"Looks scary, that's all. Pointlessly huge with fangs and claws and stuff. If it showed up on the surface, people would definitely treat it like a monster."

...Elise, you liar.

...How is any of this "looks scary, that's all"?

He walked toward the demon on the throne, looking up at it. Keeping his movements as subtle as possible, Ren wiped the sweat from his palms on his sleeves.

Overwhelming pressure, beyond any argument.

With every step closer, the Demon King's piercing gaze pinned him down, threatening to freeze his legs mid-stride.

"Human. I have received a report about you from Achendia."

The demon spoke, chin still propped in its hand.

"I am the Demon King, Versalem. Demon King, demon, Versalem — call me whatever you like. Since there is no lord-and-vassal relationship between us, I have no intention of dictating how you address me. Nor do you need to grovel."

"...Uh, hello."

"First, I suppose I should say — welcome. It is no simple matter for a human to visit this underground world, is it? Which means, conversely, that you came here with a purpose worthy of the effort."

The Demon King Versalem extended a gnarled finger, pointing.

The finger was aimed at Ren's right hand.

"The Odd-Eyed girl reached out her hand. Those elegant fingers took his right hand and gently drew it close---"

"The Goddess's Kiss."

"The instant he felt that fleeting warmth brush the back of his hand, a light the color of the empyrean blazed to life on his skin."

The Seal bestowed by the Goddess Resflaze in Heaven.

There was no mistaking it — the Demon King was pointing at the exact spot where the Goddess's lips had touched.

"At the request of my former ally Eleline, I joined with the Goddess Resflaze and the Dragon Emperor Calra to seal the Isle of the End. You are aware that the Seals are the only key to undo it, yes?"

"----"

A silent nod.

"Whether the thing you call the Encore truly exists, whether it is actually hidden on the Isle of the End — these are trivial matters to me. The same goes for whatever is recorded within the Encore. I have no desire to know."

"Meaning?"

"What I fear, as the leader of demonkind, is the unsealing of the Isle of the End itself. After the End War, that Sword Emperor went out of his way to request the island be sealed. Surely it is only natural to feel apprehension about the act of opening it?"

"...I heard the same thing from the Goddess in Heaven."

"Don't let anyone set foot in the place where that war was fought. But..."

"There's one exception."

"If somewhere down the line — decades or centuries from now — a human appears who I can entrust the whole world to in my place, then give them the Seals to break the barrier."

The words Eleline had left behind.

What lay beyond that closed door — now that Eleline was gone, no one knew.

"Now, to the matter at hand. As the holder of a Seal, the Demon King has the right to judge you. If you desire the Seal—"

"...A fight?"

Given his experience dueling the Dragon Emperor Calra, Ren had been bracing himself for a battle with the Demon King too. But just as that thought crossed his mind—

"A deal."

"Huh?"

"You want the Seal. In exchange, you will provide something I desire. 'Price and demand' — that is the demon's way of judgment. Surely you didn't think it would be some roundabout exchange of riddles like the Goddess's, or a primitive test of strength like the Dragon Emperor's?"

"...Really?"

"Ah yeah, I've heard stories like that. Some guy converted all his family's fortune into jewels and traded the whole lot to a demon to get revenge on the king who attacked his village."

Dan nodded along from behind them.

"I don't get the details, but basically, if the kid wants somethin', he's gotta pony up somethin' worth it, right? What the Demon King's asking for is a little scary, though."

"Precisely. The human in the back understands better than you do."

The Demon King Versalem let out a low laugh, then pointed his clawed fingers at them once more.

What kind of impossible task would be forced on him...

This was what the Demon King wanted. It certainly wouldn't be ordinary treasure. Something that required returning to the surface to obtain was entirely possible.

"Fine. Just tell me what it is."

"Spirited. Very well — that sword strapped to your back. Hand over Spirit Sword Vierge."

"......Excuse me?"

"Spirit Sword Vierge. That is the blade, is it not?"

"Th-that's not what I — wait! Why this sword?"

He waved both hands frantically, trying to hide the sword on his back.

"There is nothing strange about it. That is the very sword with which the Sword Emperor Eleline defeated my elder sister, the former Demon King Elise. It carries deep significance. Furthermore, we have been advancing our research into spirit armaments here in the Underworld. Acquiring that sword would propel our research forward by leaps."

"Th-that's — why — this isn't — it's my... well, it's borrowed... but it's the sword I use! If I hand it over, I won't be able to fight!"

"I shall give you a demonic treasure blade. In sharpness alone, it surpasses even a spirit sword."

"...But—"

"However, it is cursed, so be prepared to lose ten years of your lifespan with every swing."

"Who'd be prepared for that!?"

Ren took a deep breath and exhaled slowly. He steadied himself and sorted through the situation. He had to get the Seal, no matter what. But he couldn't hand over Spirit Sword Vierge either.

"What if I found you a different spirit armament?"

"Do you truly believe spirit armaments that match the Seal's value grow on trees?"

"...R-right. Then something else, please. Preferably something I can actually manage."

"Hmm."

The Demon King rested a hand on his chin, thinking.

"Very well — I'll hand over the Seal, but in exchange, you become my subordinate. How about that? I've been wanting a human subordinate. You would work in this palace for the rest of your life."

"For life!? That's way too long!"

"All you need to do is agree and the Seal is yours, right here, right now."

"That's the problem — I can't agree to that..."

A bad feeling was creeping in. The leader of all demons, indeed. The Dragon Emperor Calra had been tough to persuade, but this Demon King was a different kind of headache entirely.

"Something else—"

"Then hand over the paradise island of Spica, in its entirety—"

"It's not mine to give!"

"Then bring me three chicks of the Purgatory Bird, a species that went extinct a century ago—"

"You just said they're extinct!"

"A sand whale that swims through the dunes of the Underworld. Be careful — it dies the moment it leaves the sand."

"...How am I supposed to carry that?"

He didn't even have the energy to raise his voice anymore.

This was hopeless. Even if he had a hundred more requests to fulfill, he couldn't see himself pulling off a single one.

"Come on, cut me some slack here..."

"No."

The Demon King's answer was instant.

"Too bad, human. It seems you lack the qualifications. Give up on the Demon Seal."

"You can't be serious!"

"I will not give the Seal to a human who cannot meet my price."

"Listen here, you..."

Young.

But the voice that rang from the ceiling carried a strange force behind it.

"I'm telling you to hand over the Seal already. You stupid little brother!"

A dull crunch echoed through the hall.

That was the sound of Elise's heel drop, descending from the ceiling and burying itself in the Demon King's skull.

"Gwoaaaaaah!? My head just caved in!?"

"Listen here, you — don't push your luck with me..."

"S-s-s-sis!?"

Faced with a little girl less than half his height, the Demon King Versalem slid right off his throne. He scrambled backward on all fours, trying to flee — and then.

"Hey, Demon King."

The one who grabbed him by the scruff of the neck was the dragon girl.

"Hand over the Seal. Now. Unless you'd like me to reduce this entire palace to cinders."

"K-Kyelse!? What is the Dragon Princess of the surface doing here!?"

"Things happened."

"Sis, this is bad!! Hey, Lulu, what is the meaning of this!? I can accept my sister being here, but nobody told me the Heavenly Silver Dragon's princess was coming to the Underworld!"

"My apologies for the late report."

Lulu, standing in the middle of the hall, answered breezily, not a hint of guilt in her tone.

"...Tch. But I will not yield. Even surrounded by my sister and the Dragon Princess—"

Then came the sound of approaching footsteps. Every eye in the room turned at once. A golden-haired Archangel appeared, cheeks slightly flushed, carrying a wine bottle in each hand.

"Sorry to keep you waiting! My, my — the demons' wine is nothing to sneeze at. What a lovely little viewing party that was."

"The Tyrant Angel of Heaven too!? S-sis, why!?"

"Things happened, part two."

"The palace is done for!!"

The leader of all demons clutched his head and wailed.

"Oh, Ren. You still haven't gotten the Seal?"

"The thing is, he said I need to make a deal for the Seal. And the demands he threw at me were pretty ridiculous, so I was stuck."

"Oh my, oh my. ...That simply won't do, will it?"

"You dare withhold the Seal? A mere Demon King with that kind of nerve?"

"You. Do you even understand your position right now?"

"Hiiiiiieeeee!?"

A Demon King whose appearance alone would have any human trembling in fear — now quivering himself, surrounded by a handful of dainty girls.

"Hey, kid — what's goin' on here?"

"Beats me..."

Ren, Dan, and Misty stared blankly at each other. Meanwhile, the only one keeping a straight face was Lulu, who moved to the Demon King's side.

"Demon King, why not simply come clean?"

"...Come clean? What do you mean?"

"Yes, Ren. I'm embarrassed to say this, but—"

Lulu pointed at the Demon King, who was surrounded by the Three Princesses.

"The jewel containing the Demon Seal — the Demon King lost it about thirty years ago."

"......Huh? He... lost it!?"

"I'll let you fill in the rest."

You can't hand over what you don't have.

But confessing something like that from the position of Demon King was absolutely out of the question — especially with no telling what his sister Elise would say.

"I see. So that's why he was throwing out impossible demands — to avoid having to give up the Seal."

"...I'm speechless."

"...Seriously?"

"...I've lost all interest. I'm going to go have another drink with Achendia."

Kyelse, Elise, and Fear each let out a deep sigh.

In stark contrast, the leader of Venus Light nodded with a look of genuine satisfaction.

"Oh, I totally get it. That kinda thing happens all the time in our party. I've lost count of how many times I've lost the party wallet. And Silk lost the map to a hidden realm right in the middle of the realm itself. Rin even dropped treasure we'd already grabbed once."

"That's exactly why I ended up carrying everything — the wallet, the map, the treasure, all of it..." Misty muttered.

Come to think of it — Ren noticed it just then — Misty's pack was heavier than Dan's.

"See? This is what I'm dealing with. Boss, you should be ashamed."

"Ha ha ha! What's wrong with that, Misty? If the Demon King of the Underworld can lose stuff, then it's no big deal when we do!"

"But this time, the Demon Seal isn't something you can just write off as lost."

Lulu, at the Demon King's side, turned to face them with a serious expression.

"Wouldn't you agree, Ren?"

"...Yeah. This time the stakes are too high."

Without the Demon Seal, they couldn't enter the island that was the decisive battlefield of the End War. And if they couldn't land on the Isle of the End, they might never obtain the Encore.

"The Seal — let us help you look for it."

"No. You are our guests. I couldn't possibly trouble you."

Lulu produced a map from somewhere and murmured, "The floor plan of the Demon King's Palace," before spreading the foldable map out in both hands.

"We'll have the entire staff searching. Let's enlist the Five Great Disasters and their familiars as well."

"B-but what will the Five Great Disasters think? My dignity will be—"

"We'll tell them it's a treasure hunt. Promise the palace courtyard as a reward and everyone from the Five Great Disasters down to the lowest subordinate will be thrilled."

"The entire courtyard!?"

"Don't worry. They'll get bored soon enough anyway."

Lulu jotted notes on the map as she spoke.

"Give it less than ten years and they'll abandon it, saying they don't want it anymore. The only risk is Mia claiming it as a personal training ground and sticking around, but that one's hopeless at anything besides combat. Wait about twenty years, then tell her you lent it, not gave it. She'll hand it right back."

"...You think so?"

"Trust me. I'll go relay the orders now."

Lulu rose, map in hand.

"I must take my leave, but your rooms should be ready shortly. A dark fairy will come to escort you. Please relax in your rooms until dinner."

She rattled off the instructions and swept out of the hall.

Behind her, Dan let out an admiring sigh at the flawless way she carried herself to the very end.

"Man, what a classy lady. She's nothin' like the demons I imagined. What do you think, kid?"

"...Same here. She's also got the vibe of a sharp strategist."

"Well, duh — she's the oldest member of the Demon King's Palace."

Elise said this, hands clasped behind her head.

"Luluphonica, the Demon General of Ice, is special even among the Five Great Disasters. She's lived in the palace longer than anyone and has served as an advisor to every Demon King. She insists on calling herself the Housekeeper, though."

"A Five Great Disaster!?"

"Huh, you didn't know?"

Even as she said it, Elise looked pleased at his surprise.

...Come to think of it, she said there were two left among the Five Great Disasters.

...The ones who'd shown up were the Demon General of Blaze and the Demon General of Wave, so the numbers didn't add up.

The Demon General of Ice was Lulu herself — that was why she'd left herself out. That offhand remark had been her version of a hint.

"Didn't think she'd be the mischievous type..."

"Being mischievous is a demon's defining trait."

"Yeah, fair point. But Elise, you seem really close with Lulu?"

"What do you mean?"

"Well, the Five Great Disasters were originally candidates for Demon King, right?"

"Those Five Great Disasters used to be Demon King candidates, but I won the Demon King selection and made them my subordinates."

They were demons who had once vied against each other for supremacy over the Underworld.

And yet those two — Elise tackling Lulu in a hug the moment she saw her, and Lulu patting Elise's head in return — could they really become that close?

"It's something of a tradition at the coronation ceremony."

The one who answered was the Demon King Versalem himself, seated on his throne.

"Four of the Five Great Disasters fought my sister for the throne, but the Demon General of Ice was different. She had already decided from the start that my sister was the rightful Demon King. The battle she fought against my sister was merely a formal acknowledgment — a rite of passage, so to speak."

"And that's how I officially became Demon King."

"Is that a rule?"

"Nope, not at all."

The former Demon King shook her head without hesitation.

"But Lulu did the same for the Demon King before me, too. She's been the Housekeeper of this palace since before I was even born."

"...That's a whole different level of seniority."

"Lulu really took care of me, too. Anyway, moving on—"

Elise closed her mouth and spun around.

With a fearless smirk on her lips.

"Hey, Fear? Gimme one of those wine bottles you're carrying."

"Here you go."

"Thanks. ---- Now! You, stupid little brother! Get off that chair and go look for the Seal yourself!"

"Guhahk!?"

The wine bottle Elise hurled struck the Demon King square in the head once more.

"Huuuman. Huuuman. Feeding time."

The door opened at the bell's chime to reveal a fairy floating in midair.

A dark fairy — a fairy with translucent wings marked by black patterns. Adults grew to about sixty centimeters. Not as large as a greater fairy, but among hovering fairies, they were said to be one of the biggest species.

...On the surface, they're considered critically endangered.

...Who would've guessed they'd migrated to the Underworld? That's a huge discovery.

Apparently, over four thousand dark fairies worked as housekeepers in the Demon King's Palace under Lulu's command. The dark fairies were guaranteed a safe home, and the demons got convenient servants. An ideal symbiosis.

"Your feed's ready."

"...Feed?"

"Dinner, some call it. I can't tell the difference, though."

The dark fairy in an apron nodded sagely.

"Follow me."

"You're showing us the way? Thanks."

Ren followed the dark fairy through the empty corridors. He met up with Kyelse and Fear along the way and continued deeper into the Demon King's Palace.

The Demon King's Palace — the "Crimson Grudge Pavilion."

Contrary to what "banquet hall" might suggest, the room was a great hall carpeted in an appetite-killing shade of blue-green mold. A table at the center was draped with a blindingly golden tablecloth, and more than thirty chairs were arranged around it.

"Ah, Ren's here! Over here, over here!"

Elise, seated at the center of the table, waved him over enthusiastically.

"My, Elise — isn't that Versalem's seat?"

"It's fine, it's fine. He's skipping dinner to go search for the Seal. He lost it, so he needs to reflect on what he did."

The Demon King's sister slapped the seat next to her.

"C'mon, Ren, sit next to me! Even the top aides of the Five Great Disasters never get to sit next to the Demon King. It's a super exclusive spot!"

"...I crack under pressure, so that's a no from me."

"Now, now, Elise. Ren's seat is not beside you — it's over here."

The housekeeper girl quietly pulled out a chair.

Knowing now that she was the most senior of the Five Great Disasters — Luluphonica, the Demon General of Ice — made it hard not to tense up, but Lulu herself wore her usual poker face.

"Since you've come all the way to the Underworld, I'd like you to get properly acquainted with the demons of the palace."

The seat prepared for him was well away from Elise at the center. Sure enough, there was a place card that read "Ren."

"So I'm sitting here. And the other two seats..."

"Oh my? Of all people, Ren is sitting next to little old me. How delightful."

"Achendia!?"

The crimson greater demon drifted into the banquet hall without a care.

"No need to be so guarded. Believe it or not, I'm known as quite the foodie down here. I can teach you all about Underworld cuisine — you're curious, aren't you?"

"W-well, yeah."

The first thing that came to mind when Ren heard "Underworld dinner" was the Demon Realm Curry that Elise had made. Judging by that experience, it was easy to imagine the food cultures of humans and demons were vastly different.

"...Then I'll take you up on that."

"That's the spirit. Let's be friends, shall we?"

Achendia sat down with an elegant motion.

She was on his right. If that was the case, the seat on his left might be Mia — but when he peeked at the place card, it bore a demon's name he'd never heard before.

"...'Bao'? Who's that? Is there a demon by that name?"

"Wait — Lulu, what is the meaning of this!?"

A roar shook the banquet hall.

The one jabbing a finger at the place card and confronting Lulu was Mia.

"You put Achendia and Bao next to him over me? Why!? As someone who has traded blows with Ren, I should be the one seated beside him!"

"It's the opposite. If you already know Ren, there's no need to use this opportunity to get acquainted."

"Then why does Achendia get a spot?"

"She's the foremost connoisseur in the Underworld. Her table manners are impeccable, and she knows the cuisine inside out. She's the best possible companion for Ren."

"Grk..."

"Now, don't look so dejected. Mia, your seat is over there."

Lulu pointed to a seat diagonally across from Ren — directly facing the two members of Venus Light.

"...H-hey, Misty. What do you think they serve at a demon banquet...? What if it's some god-awful stuff?"

"No worries. I don't need to eat, so I'll give everything to you, Boss."

"That's exactly what I'm worried about!!"

The grown man practically whimpered as he clung to Misty.

Mia studied the pair from afar, staring at them intently.

"Those two?"

"Indeed. They may not look it, but they're quite experienced with surface expeditions. You could learn a thing or two from their stories. Think of them as acquaintances and try striking up a conversation — even someone as tongue-tied as you."

"Wh-who are you calling tongue-tied?"

Mia spun around and stalked off, flustered.

"Mia is the same as ever. A Five Great Disaster really ought to carry herself with more refinement."

"...So who's this Bao?"

"Ah, that."

Achendia, seated to his right, curled her shapely lips into a smile.

"They're already sitting next to you."

"Huh — WHAAAAT!?"

He nearly toppled out of his chair. In the seat to his left — the chair that had been empty just seconds ago — a demon he'd never seen before sat there as if it had always been.

"----"

A large demon wearing an eerie black-and-white mask.

A cloak woven from straw-like material covered its entire body, making it impossible to tell what lay underneath.

Creepy?

No — it was beyond creepy. It was an existence that defied comprehension entirely.

"......Ohhh... Ohhh..."

What leaked from the gaps in the mask might have been a voice — or just the sound of breathing.

So this strange demon was Bao?

"----"

"Uh? Um. Erm... hi."

"......Ohh... Ohhh..."

"Oh my, Bao seems to have taken a liking to you."

Achendia rested her chin on her hand, amused at the demon looming over Ren.

"Bao is one of the Five Great Disasters — the Demon General of Curse. The last member is away from the palace, so among the Five Great Disasters you can meet here, Bao is the final one."

"...Demon General of Curse."

"Never been to the surface, so humans wouldn't know about it, right?"

Achendia accepted a wine bottle from a dark fairy.

She poured the milky-white liquor into her glass.

"Bao's a relative newcomer, actually. The previous coronation was supposed to be contested by me, Mia, Elise, Lulu, and the absent Demon General — just the five of us. But when we went to the ritual chamber, there was a demon nobody recognized just... waiting there. That was a surprise."

"And that was..."

"Bao, yes. The one who would become the Demon General of Curse. As for appearing before a human — I think the last time was Eleline's assault on the Demon King's Palace? Maybe the Encore even has a record of the battle with Bao."

And then the dark fairies came streaming out of the kitchen one after another.

The dark fairy that had guided Ren here had been dressed as a housekeeper, but the ones hovering around the hall now wore adorable little chef hats and cooking uniforms.

"It's feeed time."

"Also called an appetizer. I can't tell the difference, though."

Each tiny body carried a single plate of food.

"Salad of seafood from the Midrata Cursed Sea. Served with the chef's special sauce."

It was a seafood salad — white seaweed with spots that looked an awful lot like mold, tossed with a crustacean that resembled a spider, all dressed in what passed for dressing.

"...The plating looks like human food, at least. And there are forks and knives."

"Borrowed from human customs. But demons come in all shapes and sizes, so plenty of them can't hold a fork. That's why nobody cares about how you eat. Grab it with your hands, shove your face into the plate — whatever works. Pretty relaxed, don't you think?"

The Demon General of Blaze sipped her aperitif.

"If there's one rule at this dinner, it's 'finish everything on your plate.' You don't have to eat as neatly as Bao, of course."

"Wait — hold on, what happened!?"

The appetizer plate was suddenly empty.

The salad seaweed, the bizarre crustacean, even the dressing — every last drop had vanished without a trace.

"When did you eat that? And how, with a mask on!?"

"Why don't you ask Bao?"

"......Ohhh... Ohh..."

No matter how hard he listened, the only sound was that incomprehensible breathing.

Achendia did seem to understand Bao's thoughts, though, so maybe there was some kind of rhythm or pattern to it.

"Anyway, I should deal with my own plate first..."

How did it taste?

No, the bigger question was whether a human could even eat this safely.

"You don't need to poke at it so timidly."

The great demon of flame shook with amusement.

"This seaweed is moon jelly weed — it's a favorite of the fish here in the Underworld. Boiling it in hot water brings out a sweet aroma, which is why it's also called 'fruit of the sea.' The garnish is eight-legged shrimp. Those have a mild flavor, so they're there to complement the seaweed. As for the dressing... yes, they've added a few drops of surface citrus juice. That's to cut the briny smell. It also serves to balance the sweetness of the moon jelly weed with some acidity. A good choice."

She'd identified every component of the appetizer at a glance, without even tasting it.

"Go on, Ren."

"O-okay, just a bite..."

He wound some seaweed around his fork and brought it to his mouth.

"How is it?"

"......It's good. ...Wait, it's actually really good!?"

The instant it hit his tongue, a powerful oceanic aroma flooded his mouth.

But just as Achendia had explained, the citrus juice had thoroughly eliminated the fishiness, leaving only the rich taste of the sea.

As for the intimidating-looking eight-legged shrimp — it tasted exactly like surface shrimp. If anything, the firmer texture might have given it an edge over the real thing.

There was a hint of hidden seasoning — vinegar, perhaps? It gave the salad a light, refreshing quality, making it the perfect appetizer.

"Human-face fish soup."

Next came a deep bowl of green soup.

"For honored guests, it's served head and all. I don't know what that means, though."

"Ugh... now that's an unsettling dish..."

"This is only the beginning. The rule is to eat everything, so if you're flagging already, you won't last. Here — today's course menu."

"That many!? What is this — twenty dishes from appetizer to dessert!"

Ren couldn't help but yelp when he saw the course list.

"The main dishes alone are ten plates..."

"No time to panic. Look, the next dish is already here."

"That's way too fast!"

As Underworld dish after Underworld dish piled onto the table, Ren was already at his limit.

Two hours later.

"I can't... No more food. Can't move..."

Ren lay slumped across the table, idly watching the dark fairies bustle around preparing after-dinner tea.

"Eleline was the same way. Humans really don't eat much, do they?"

Achendia nibbled at a tea-time pastry.

In front of her, empty wine bottles were stacked into a tower.

"...Not fair. You made me eat everything and all you had was wine."

"Your friend Fear is the same, isn't she? Angels and demons are alike in their love of drink. Though being fond of it doesn't necessarily mean you can hold it."

Achendia glanced pointedly to the side.

There sat Mia, face beet-red, completely wasted.

"...I know... I'm the one nobody likes..."

The brown-skinned demon sniffled.

"No family. No friends. Even my subordinates can't stand being around me... I know that... Achendia has tons of followers, and Lulu is adored by the dark fairies, and even Bao has loyal right-hand demons..."

"Hey now, hold on there, Mia."

Mia slumped, dejected.

The one who clapped a firm hand on those drooping shoulders was the man who led Venus Light.

"Listen up. You're missin' somethin' important."

"...Something important?"

"That's right. Look, Mia — you can intimidate your subordinates with raw strength all day long, but that ain't gonna earn you a real bond with 'em. What you need is guts. Heart. You know it deep down, don't you? All that heavy armor you wear ain't gonna give you authority."

"...Th-that's—!"

Mia's eyes went wide, shaken to the core.

—Unparalleled regeneration and endurance. The strongest body among all demons.

—So why would someone like that need armor?

Dan couldn't have known the specifics of Mia's abilities, of course.

But the seasoned swordsman's instincts had picked up on the incongruity of that armor. He'd realized it wasn't there to protect Mia's body.

"Strapping on heavy armor and a big sword to project authority — sure, human kings do that too. But I can tell. You're conflicted. Dignity and presence — those come from inside you. They don't come from armor. You already know that, don't you?"

"...Ngh."

The brown-skinned demon clenched her teeth.

"B-but what should I—"

"Easy now, Mia. Leave it to me."

Dan gently patted the trembling shoulders.

"Come work under me for a bit — broaden your horizons. The thrill of adventure across the wide-open world, the joy of sharing a victory with your comrades. Experience that, and you'll grow as a person. Your presence will come naturally. Join my party right now and you'll be Member Number Five — top brass. Welcome aboard."

"Huh?"

The white-haired girl beside him turned around, startled.

"That's a bit—"

"What's the matter, Misty? We always welcome new family."

"...No, it's nothing... You're seriously recruiting a demon, though...?"

Misty quickly looked away.

"Top brass!? You really mean it!?"

Meanwhile, Mia leaped to her feet, electrified.

"You'd let someone like me join!?"

"'Course I would! We broke bread together — that makes us more than just party members. I call my party family."

"Family..."

"And Member Number Five is a limited-time offer."

"...The party only has four members. She'd just be the fifth person." Misty muttered under her breath.

"Got it. Then I'll train under you to build my presence."

"Ha ha ha! Leave it to me. You're one of us now, family. And now that it's settled — a toast! Just call me Boss."

"Boss!"

The two poured each other drinks, fast friends already.

"What is that about?"

"...Mia really is hopeless when it comes to brains."

"......Ohhh...?"

Ren exchanged glances with the Demon General of Blaze and the Demon General of Curse, not quite believing what he'd just witnessed.