"Seriously, let's go to the hospital?"

Ichika continued in an earnest voice, the piercing in her right ear glinting.

"Itsuki-chan, ever since February started, you've been eating even less than Miku — and she's a light eater, you know?"

"You should have Dad take a look at you."

"There's no need to worry, Yotsuba. I'm sure I'll recover soon—"

"No way!"

Yotsuba shouted forcefully.

Her usually carefree face was filled with alarm.

"This isn't like Itsuki at all... It's yakiniku and she didn't go back for seconds even once — something's definitely wrong with her!"

"If you think about it calmly, doesn't the average high school girl not go back for seconds over and over?"

"No way, Itsuki just said something reasonable about how much she eats...?"

"C-calm down, Miku. As you can see, Itsuki right now is completely out of her right mind... We're the ones who need to stay at least a little level-headed here..."

Being worried about this much is honestly getting rude, you know!? I wanted to shout.

It was true that I usually ate a bit on the larger side, but still.

Then again, maybe everyone was so anxious that they were losing their composure too.

"I'm going back to my room. I have to work through the practice problems Uesugi-kun made for me."

"You sure? Itsuki-chan, you pulled an all-nighter yesterday too, didn't you?"

"Rest a little. Right now you're a complete nervous wreck over these exams."

See, your skin's all rough too! Nino said, holding up her phone's front-facing camera to show me.

It was true, I was quite worn out...

The way my appetite had thinned over the past few days was surely the pressure of the entrance exams, too.

I knew it perfectly well — what mattered most for exams was managing your health.

And naturally, eating habits were a crucial part of that.

But whenever I thought about the entrance exam for my first-choice university, just ten days away, my appetite simply refused to come.

"Are you feeling all right?"

"Of course," I answered Miku's question at once.

Wracked with guilt, I'd put on a brave front because I didn't want them to worry.

Maybe it was because I was eating so little, but I couldn't quite get my energy up — still, I didn't want to let any weakness show.

I had the feeling everyone was just being oversensitive out of worry for me.

Ichika had become a popular actress, Nino and Miku had both gotten into culinary school, and Yotsuba's recommendation-based admission was settled.

I was the youngest, and I was the only one — I didn't want to cause everyone any worry.

I had to pass, no matter what.

That was the first step toward independence!

Last month I'd said something childish to Ichika, but I wouldn't do anything like that again.

Lately I'd even been using the exam-cheering goods Ichika gave me as thanks for the big cleanup, so I had to be getting closer to being an adult.

"That reminds me, about 'Quintuplets' Day'—"

Stoking my resolve toward the entrance exams, I decided to change the subject.

"We were planning to get together and hang out this coming Saturday, but we hadn't decided what to do yet, right? How about we make chocolate?"

"Make chocolate?"

I nodded to a blank-faced Miku, my heart fluttering a little.

"Actually, I ran into Raiha-chan in town the other day. The topic of Valentine's came up. Apparently Raiha-chan wants to hand out chocolate to her friends in class."

"Cute! That's so like Raiha-chan~"

Yotsuba bobbed the green ribbon in her hair, while Nino wore a dubious expression.

"Will that be okay? Doesn't Fuu-kun's place not even have a TV? You can make fancier chocolate if you've got an oven."

"Yes. So actually, I was thinking of inviting Raiha-chan over on Saturday."

"I see. You mean offering up the Nakano kitchen as the place to make chocolate."

Sharp as ever, Ichika.

"I've already worked it out with Raiha-chan. When I asked her if she'd like to make chocolate at our house,

'Really!? I've always wanted to cook in a fully equipped kitchen, just once!'

'I want Nino-san to teach me how to make chocolate!'

'Besides, if I make it at home, Dad gets all annoying about it — "There's no way it's for a boyfriend, is there!?"'

is what she said—"

Oops.

That was a slip. I had to cover for it.

"—is what she said. I'm sorry it's after the fact, but what do you think?"

When I asked, my sisters were overjoyed.

"I'm all for it! I'd been thinking I might bring some Valentine's chocolate for the people at my agency, too."

"I want to give some to the manager at the bakery, too. He's always looking out for me."

"I'll hand mine out to friends. As for Yotsuba... well, I guess I don't even need to ask."

"Huh!? ...Nino? What do you mean?"

"Oh-ho? Do I really have to spell it out for you? I mean, you said it yourself after the school festival, didn't you? Something like, 'If you ever let your guard down, I'll snatch him away.'"

Nino curled her pale-pink lips into a smirk, putting on the face of a femme fatale.

Yotsuba, on the other hand, flushed, lowered her eyes for just a few seconds, and then,

"It's fine. I'll give it to him properly."

She lifted her face and put it clearly into words.

Of course, the one she'd be giving chocolate to had to be her boyfriend, Uesugi-kun.

Nino had openly declared to Yotsuba before that she hadn't given up on Uesugi-kun either, so it looked like she'd be giving him chocolate too.

Ichika and Miku might give him chocolate as well, as thanks for everything.

I wanted to give him some too, very much.

Even now, right before the exams when he was so busy, he was still tutoring me, and Uesugi-kun had truly helped me for about a year and a half.

"I can't wait~!"

"Yeah. It might be the first time we've invited Raiha-chan to this house."

"Our kitchen's big, but six people cooking in it is probably a bit cramped. Maybe some of us should make chocolate on another day. We could just have her teach us how on Saturday."

"There's no problem with Ichika's plan. Let's go out of our way for our little sister. It'll be a good chance for Itsuki, too."

"Me?"

"Fuu-kun said it the other day, didn't he? 'At Itsuki's current academic level, if she goes into the exam in perfect condition she should pass.' So take Saturday off from studying."

If you rest, maybe your appetite problem will clear up too! Nino said with a smile.

I nodded while observing my sisters' expressions, but nothing seemed out of place.

"Then, Saturday it is. Thank you all."

After returning to my own room, I worked my red phone.

[I tried bringing up the matter with everyone, but I couldn't get any hints.]

When I sent the message to Raiha-chan, it was marked read right away.

Raiha-chan had traded her flip phone for a smartphone around last autumn.

"I can join the class group chat now!" she'd been so thrilled.

The whole reason Uesugi-kun became our tutor in the first place was to help with the family finances.

Apparently things used to be so tight they were practically about to go up in flames, but their finances had recovered enough that Raiha-chan could have a smartphone.

You really worked hard, Uesugi-kun. Well done.

[I see~ then how about we go digging on Saturday? Into who the fake Itsuki-san is.]

Reading Raiha-chan's reply, I organized the situation in my head.

A moment ago, I'd told everyone I'd talked about making chocolate when I ran into Raiha-chan in town.

But the truth was entirely different.

In the first place, I had never run into Raiha-chan in town at all.

I'd noticed something was off yesterday, when Raiha-chan and I were having an idle chat on the phone.

'By the way, I'm really looking forward to making chocolate.'

'? What do you mean?'

'Huh? What are you talking about? You're the one who invited me, right, Itsuki-san?'

When I heard that, I got quite confused.

According to Raiha-chan, she'd met me in town on January 31st.

That's right. The words from Raiha-chan that I'd just relayed to everyone were things Raiha-chan herself had told me yesterday — "this is what you said that day."

To make matters more confusing, they weren't words I'd heard directly on the 31st.

According to Raiha-chan, she'd talked with me about making chocolate on the 31st and made a promise to come to the Nakano house — but of course I had no memory of any such thing.

In that case, there was only one answer.

Someone among the quintuplets had disguised themselves as me and met Raiha-chan in town.

Someone had been secretly acting as the fake Itsuki.

But who? And for what purpose?

"Pardon the intrusion."

February 9th, Saturday, twelve-thirty on the dot.

The five sisters, in their casual clothes, greeted Raiha-chan at the entrance when she visited the Nakano household.

"Welcome! Welcome to the Nakano house!"

"Yotsuba-san, long time no see! We haven't met since the New Year's shrine visit, right?"

Her smooth black hair, tied with a small pink ribbon, bounced as Raiha-chan hugged Yotsuba.

But then, as if she'd suddenly remembered something,

"Here you go. It's nothing much."

She held out a paper bag she'd been carrying in her right hand.

"It's some sweets my dad got from a business contact."

"Oh my, how thoughtful of you. Thank you."

Watching Ichika, who was standing beside Yotsuba, accept it, I exchanged words with my sisters in a low voice.

"Raiha-chan really has it together, doesn't she?"

"Fuutarou's never once brought anything."

"Forget that — back when Fuu-kun first came to this house, he tackled me to the floor right after I'd gotten out of the bath. Well, it was an accident."

"Nino-san, did you say something?"

"Nope, nothing!"

Apparently deciding it would be too cruel to expose her brother's disgraceful behavior, Nino clammed up.

When I first met Raiha-chan she was still in elementary school, but now she was a first-year in middle school.

She'd always had a bright, dependable personality, but lately she seemed even more grown-up.

"So amazing!"

But then.

The moment we showed her into the living room with its open ceiling, Raiha-chan let out a cheer.

"I was surprised when I heard it was the top floor of a tower condominium, but the Nakano family really is rich after all! The kitchen's huge! And the stove's all-electric! I'm so jealous, an oven... Wha— is this the dishwasher I've heard rumors about!?"

"Hey, hey, Raiha-chan. The view from the balcony is amazing too, you know? Want to see?"

"Can I!? Thank you~!"

When Ichika led Raiha-chan out onto the balcony, a great cheer of "What is this~!?" went up.

Somehow, it was nostalgic.

"Back when we first came to this house, we were just like that, weren't we~."

Apparently struck by the same thought, Yotsuba's cheeks softened.

"Nino was really hyped up."

"Oh? You were right there with me, Miku. You were over the moon about the size of the TV."

"I'm glad Raiha-chan's in such a good mood."

As I overlaid our younger selves onto Raiha-chan, I couldn't help feeling warm.

Still, I couldn't let my guard down.

Today's mission was making chocolate.

And on top of that, the search for the fake Itsuki!

"On second thought, I'll help you search for the fake Itsuki-san too."

Rewinding the clock — the night of February 5th.

On the video call I'd started in my room after sending the message, Raiha-chan volunteered.

"You're curious about the fake Itsuki-san too, aren't you?"

"Of course."

The thought of someone pretending to be me and doing who-knows-what just didn't sit right.

I did think I couldn't afford to be hunting a culprit right before the exams, but—

"It might be a good distraction. According to Uesugi-kun, what matters for me now is getting my mind and body in order for exam day."

"You've been working so hard the whole time, Itsuki-san. My big brother said it too, you know? 'Itsuki's grown a lot, and I can't afford to lose to her either.'"

"Uesugi-kun did!? ...Hearing him say that about me makes me really happy."

"Though he also said, 'By the way, the results of the past exam I did today are... don't look, Raiha! It's an embarrassing score so absolutely don't look!?' which was kind of annoying. He's out at his part-time job right now, though."

"Uesugi-kun really loves that bit..."

To think he was pulling it on his own family too.

Anyone who knew him well would understand, but the "don't look" was just a feint, and he'd surely gotten a perfect hundred again.

"Why not just ask everyone directly about the fake Itsuki-san?"

"No. Since they disguised themselves behind my back, I can't imagine they'd honestly confess. When I brought up making chocolate earlier, no one said a thing."

"Ah, I see."

"I want to catch the culprit somehow. If I do, I feel like I could carry that momentum into the exams... ah, but if I can't find them, then I might fail on the day, too...!"

"C-calm down, Itsuki-san? Getting too nervous before the real thing isn't good for you."

Ugh, Raiha-chan was right.

It would probably be a wise move to lose myself in solving a mystery for a little while, to forget the pressure of the exams.

It might even become the thing that fixes my loss of appetite.

"Ehehe, it's like I've become a detective from a mystery novel. I want to play the part of Watson-kun!"

"Do you read mystery novels?"

"I don't read them at all, but I know the names of the great detective Holmes and his assistant Watson-kun. Have you ever read mysteries, Itsuki-san?"

"Hoping it might help with this culprit hunt, I borrowed one from Ichika as a textbook of sorts."

"Ooh, what kind?"

"Agatha Christie. It was very interesting."

It made for a little bit of a study break too, so it was a real help.

Still, the one we'd be playing wasn't the great detective Hercule Poirot who appeared in the book.

As Raiha-chan wished, let's make it the world's most famous detective-and-assistant duo.

"Let's organize the information about the culprit, Watson-kun."

"Okay, Holmes-sensei! So, like I told you, I met the fake Itsuki-san on January 31st. The time was around five-thirty in the evening, I think."

"And the place?"

"In front of the station! I spotted Itsuki-san walking in her school uniform and called out to her."

"And at that time, the fake Itsuki was speaking in my manner of speech, right? When you talked, did you notice anything?"

Raiha-chan let out a "hmmm," as if reeling in the threads of memory.

"I don't know where she bought it, but she was carrying a handbag with chocolate inside. When I asked, 'Valentine's is coming up — are you giving it to someone?' she said, 'I'm thinking of giving it to someone important to me.'"

"Chocolate... and someone important, was it."

"The fact that the culprit went to the trouble of disguising as you means, in this case, it'd be someone important to you, right? Could it be — someone you like!? Itsuki-san, are you in love!?"

Raiha-chan was suddenly all fired up!

That reminded me, Uesugi-kun had said, "I don't know why, but ever since Raiha started middle school she's gotten precocious all of a sudden."

Surely she hadn't gotten a boyfriend at school... No!

I'm not Uesugi-kun's father, but it's still too early for that kind of relationship!

Raiha-chan was terribly adorable, but from what I'd heard, she shouldn't have a boyfriend.

"Please. Won't you tell just me, in secret?"

...No? Raiha-chan gazed at me through the screen, her eyes faintly misting over, with a face that stirred up every protective instinct.

Gah, too cute!

I felt like I'd confess on the spot, like a suspect served a katsudon²during interrogation.

"R-regretfully, there's no one I'm interested in at the moment."

"Aww, too bad."

"Still, the phrase 'someone important' is on my mind."

Someone important to me.

Ichika. Nino. Miku. Yotsuba. Dad. Grandpa, who runs the hot-spring inn.

And of course, Uesugi-kun.

Raiha-chan.

My friends from school.

Ebata-san, who serves as Dad's secretary and often looks after us.

And then there's Shimoda-san, the cram-school instructor at my workplace who's also one of Mom's former students.

Did the culprit intend to impersonate me and give chocolate to one of these people?

Valentine's was right around the corner, so could that be connected too?

"On the 31st it was an optional-attendance day, and I was studying at home. Everyone was home in the morning too, but they went out after that."

Nino, Miku, and Yotsuba in the early afternoon.

Ichika went out around four, saying she had a drama shoot, but I didn't know if that was true.

Knowing Ichika, there was a chance it was a bluff to build an alibi.

"Raiha-chan, was there anything you noticed?"

"Hmm... ah, Nino-san might not be the culprit! Because there wasn't any perfume smell. Nino-san always smells nice when we meet outside, right?"

I see!

It was true that Nino always put on perfume when she went out.

"There's a possibility she deliberately left it off to play me, but given Nino's personality, she'd choose perfume over the quality of her disguise. Nice work, Watson-kun!"

"Ehehe, thank you~."

"Is there anything else you remember?"

"After we met, she treated me to cake at a cake shop, but I didn't notice at all that she was a fake. Quintuplets really are amazing."

"We do have the same face. But since we have no leads, it might be best to do some probing on Saturday."

"Ah, I thought of a good plan! How about, for example, Itsuki-san disguises as Nino-san and questions someone else?"

It was true that if I impersonated one of my sisters other than myself, the fake Itsuki might carelessly let something slip.

It was a clever idea, befitting Uesugi-kun's little sister, but—

"Regretfully, that plan looks difficult."

"Eh? Why?"

"We're quintuplets. If one of us disguises ourselves it's hard to tell us apart, but it's different among us sisters. We can tell each other apart at a glance, so the culprit would see through the disguise."

"I see... so the disguise plan is a bust."

Raiha-chan was visibly downcast.

To cheer her up, I strung my words together.

"Please don't be discouraged. Raiha-chan, you're as much of an asset as anyone could be. If you talk with the quintuplets other than me, you might remember the sense of wrongness you felt when you met the fake Itsuki."

"A sense of wrongness, huh."

"From there we can advance our deductions. Raiha-chan, you're an important asset, and you're my partner. I'm counting on you. Let's catch the culprit no matter what."

"Itsuki-san..."

"Before a tragic victim appears!"

"Ahaha. I don't think the fake Itsuki-san will be committing murder, but I'm counting on you too! Let's solve this case together!"

Good — judging by her bright voice, it sounded like she'd cheered up.

And so, the decisive battle would be Saturday.

February's 'Quintuplets' Day' — the day we'd make chocolate.

"Huh? Nino-san, you're not wearing nail polish today, are you?"

The flashback ended, and we were back in the Nakano household's system kitchen.

Raiha-chan, wearing the apron she'd brought along, asked the question.

Nino, dressed in a matching pale-purple apron, answered with an "Ah."

"Usually I keep it on even while cooking, but today I'm teaching everyone, so I took it off. We're at home, so I'm not wearing perfume either."

"I see~. I was looking forward to your nails, Nino-san. They're always so cute."

"Really? Maybe I'll put some on after we're done cooking."

"Hey, hey, Nino. How about painting Raiha-chan's nails too?"

At Yotsuba's voice, Raiha-chan looked a little surprised, then her young eyes filled with anticipation.

"Nino-san, is that okay?"

"Of course. I'll teach you how to do it, too."

When Nino played the big-sister role, Raiha-chan hugged her with a "Thank you~."

At that angelic adorableness, the usually dignified Nino's expression melted like cheese.

"Want some nail polish? Don't you want your onee-san's hand-me-downs?"

"Ah, Nino, no fair! Raiha-chan, do you want some brand-new accessories? I found some in my room last month. Want to be a girl who's a little grown-up for her age?"

"If that's how Ichika's going to play it, then so will I! Raiha-chan, isn't there anything you want? I'll give you anything! Or rather, I'll do anything for you!"

"Aren't you selling off even your soul and going all-out to reel her in...?"

"Oh, that's right, Raiha-chan. If there's anything you don't understand about making chocolate, don't hesitate to ask, okay? I made a lot last year, so I know the spots where it's easy to mess up."

"Really? Thank you, Miku-san!"

My apron-clad sisters, seizing every chance to spoil their guest.

Raiha-chan was probably actively trying to join the circle in order to find the culprit, too.

As I watched, thinking that, my eyes met Nino's.

The cooking teacher, with a butterfly hair clip, broke into a mischievous little grin.

"Trouble, everyone. Itsuki's getting jealous."

"Huh?"

"Sorry~! I've been fussing over nothing but Raiha-chan!"

"No, it's not like that."

"You're the youngest, so it's fine to let us spoil you a lot, you know?"

Perhaps spurred on by the words of Nino, Yotsuba, and Ichika, Miku spread both arms while keeping her usual blank expression.

"...Want a hug?"

"Honestly, please stop treating me like a child."

I used to hug everyone all the time in the past, but in front of Raiha-chan it was out of the question.

I'd be turning nineteen soon. I couldn't let myself be coddled.

I had to become more of an adult and catch up to everyone!

"Let's get started soon."

I put on my own red apron.

What we were making today were heart-shaped chocolate cookies.

"Not raw chocolate or anything like that, then?"

"What we're making today is the batch the little one's handing out to her friends, but there are five days until Valentine's, right? Raw chocolate would spoil. Chocolate cookies last about a week even when they're handmade."

And you can make a lot at once, Nino said, standing at the kitchen with a practiced air.

Just as Ichika predicted, six people cooking really was a bit too cramped.

So today's cooks were Nino, Miku, me, and Raiha-chan.

Ichika covered the entire cost of the ingredients.

That's what a young actress on the verge of going nationwide could do. Her financial power was literally on a different order of magnitude.

And Yotsuba was just observing, but—

"The ingredients are cocoa powder, cake flour, powdered sugar, eggs, and butter. Plus milk chocolate to decorate the cookies."

"I see."

"In cooking, the fine details decide how things turn out. So as prep work, you bring the butter back to room temperature, and you preheat the oven to exactly 170°C before baking the cookies."

"I see."

"All right, first, the powdered sugar—"

"I see."

"...Hey, Yotsuba? This is honestly getting a little hard to do, you know?"

Nino shot a flat glare at Yotsuba, who was observing the cooking process while firing off one "I see" after another.

Yotsuba, filming apron-clad Nino with her phone, beamed.

"Hehe. I can't let you show any openings, right?"

"Even so, you're recording the whole cooking process?"

"This is studying too! ...I want to give someone delicious chocolate as a present, too."

Yotsuba blushed earnestly.

Perhaps disarmed by that guileless expression, Nino softened her cheeks and said, "Honestly, what am I going to do with you."

"Little one, would you beat the eggs?"

"Okaay."

Raiha-chan picked up a small bowl with a practiced air, then cracked an egg one-handed.

"Amazing, you can crack it with one hand."

"Ehehe. Thanks, Miku-san. I do it at home all the time."

"Maybe I'll try it too... ah."

Miku challenged it one-handed too, but couldn't crack it cleanly.

"Surprisingly hard..."

"It really is. Raiha-chan, is there some kind of trick to it?"

"Yeah! The secret's in how you grip it. Like this, kind of like gripping a baseball..."

While Raiha-chan's friendly egg-cracking lecture got underway, Nino spoke to me.

"Itsuki, grab a biggish bowl and a whisk."

"Understood."

I took the requested items out of the kitchen shelf.

After that, under Nino and Miku's instruction, Raiha-chan mixed butter and powdered sugar with the whisk.

Partway through, my eyes met hers, and—

Sorry, even talking with everyone I can't find any hints about the fake Itsuki-san!

—she seemed to convey something like that through eye contact.

She was probably searching for some point of overlap between one of the people here and the fake Itsuki, but unfortunately it didn't seem to be going well.

We were quintuplets.

Sisters with the same face — it wouldn't be easy.

"Ah, Nino. Can I post a photo from while we're cooking on Instagram?"

"Huh? Of yours?"

"I won't show anyone's faces. I'll make it look like I'm making chocolate to bring to the staff."

"Hmph. It's a request from the sponsor who paid for the ingredients, so I'll hear you out."

"Yay! Raiha-chan, can I borrow that? Miku, you handle the camera."

After picking up a bowl with ingredients in it, apron-clad Ichika made a camera-ready smile toward Miku, who was holding up the phone.

Whoa, that's an actress for you!

A magnificent Instagram-worthy smile. She could rake in "likes" by the bushel.

"Ah!"

"? What is it, Itsuki-chan?"

"No, um, Raiha-chan. That reminds me, you ate a 'demi-glace hamburg steak'³last night, didn't you?"

I said the keyword we'd decided on beforehand for talking one-on-one.

Raiha-chan nodded with a quick little nod right away.

"It was super delicious."

"That's good to hear."

"I want to make chocolate cookies as delicious as that hamburg steak. Ah, by the way, could you tell me where the bathroom is?"

"I'll show you. This way."

When I led Raiha-chan out of the living room and down the hallway toward the bathroom—

"Did you notice something, Holmes-sensei!"

My little partner asked in a low voice, suppressing her excitement.

"There might be a hint on Ichika's Instagram. Ichika often uploads photos she takes at her work sites."

When I accessed Ichika's Instagram on my phone... there it was!

I showed Raiha-chan an image posted on January 31st.

[Today's catering looks delicious! Can't wait to eat it later~]

Uploaded along with that one line was Ichika in a sailor uniform, taking a mirror selfie in a dressing room.

On the evening of the day of the crime, Ichika had gone out for a drama shoot.

I'd been so sure it might be a bluff, but...

"In this image, you can see the clock hanging on the dressing-room wall reflected in the mirror. The time the hands point to is 5:23."

"That's seven minutes before the fake Itsuki-san and I met..."

"Time-wise, it would be impossible to take this photo at the shoot location and then meet you in town. Ichika is off the suspect list."

"Amazing, Itsuki-san, you're so sharp!"

Raiha-chan was delighted, but her lovely face quickly clouded over.

"I'm sorry. I realized something. This might be a fabricated alibi."

"Fabricated?"

"Maybe Ichika-san deliberately uploaded a photo she took before the 31st right at the crime time? That way she'd have an alibi, right?"

"A sharp guess. But that's not possible."

"Eh? Why?"

To a puzzled Raiha-chan, I enlarged the image on my phone to show her.

"Here. The cream puff Ichika is holding. It must be the catering mentioned in the comment."

"What about it?"

"This cream puff is a new product. The design splits the puff in two and sandwiches small-cut peach and whipped cream inside. And the shop name written on the pick stuck into the top of the puff is 'GLOIRE.' It's a French word meaning 'glory.' It's one of the most famous shops in the prefecture, opened by a veteran chef who trained in France. I've been there a few times myself, and the authentic Western confections were, in a word, five-star. And this cream puff... or more precisely, the product name 'Peach Puff in Early Spring'... went on sale starting exactly on January 31st. In other words—"

"This photo was taken on the 31st! The day of the crime! It's not a fabricated alibi!"

Raiha-chan got excited in a low voice.

"Itsuki-san, your memory's amazing! You really are a great detective!"

"Hehehe. I'm honored by your praise."

That's right — having written any number of reviews on word-of-mouth sites, I had a wealth of gourmet knowledge.

If I put it to use...!

"After you ran into the fake Itsuki, you ate cake at a cake shop, right?"

"Yeah. The shop where my big brother works part-time."

"That's 'REVIVAL,' which is also Nino's part-time workplace. Was the fake Itsuki eating cake too?"

"She was. I think it was some kind of chocolate cake."

"Nice work! Miku is off the suspect list too. Miku doesn't like chocolate."

"O-oh, right! To think I overlooked something so simple... Ah, maybe she ate it on purpose to make it look like she wasn't Miku-san."

"That's not possible either. 'REVIVAL' added a new item to the menu at the start of this year. It's called the 'Kyoto Uji Matcha Cheesecake.' I had some myself the other day as a study break — it was a dish where the chef's skill shone, the refined flavor of Kyoto-grown matcha and the richness of Hokkaido cheese blended in exquisite balance. When Nino brought some home as a staff meal last month, Miku raved about it too, and said, 'When I go to that shop, I'm going to keep reordering this cake for a while.' If the culprit were Miku, she couldn't have resisted the temptation of the matcha cake."

"Isn't your insight insanely good!? With your mind working this fast, you'll ace the entrance exam too!"

To Raiha-chan's praise, I demurred with a "No, no."

Hehe. To think that going around tasting all sorts of food under the name 'M・A・Y,' posting any number of reviews on the site, and checking gourmet information every day would come in handy.

Not just a great detective — the birth of M・A・Y Detective Itsuki!⁴

"With this, the culprit's been narrowed down."

"She wasn't wearing perfume outside, so it's not Nino-san. Ichika-san and Miku-san are out too. In other words, the true identity of the fake Itsuki-san is..."

"Yotsuba."

But the mystery still remained.

Why was Yotsuba buying chocolate while wearing my appearance?

And just who was this 'someone important'?

Back in the kitchen, Raiha-chan and I resumed cooking with everyone, faces perfectly innocent.

We made the cookie dough as Nino instructed.

We wrapped the dough in plastic wrap and let it rest in the refrigerator for a while.

After about an hour, we carefully rolled the dough out with a rolling pin and cut out hearts with a cookie cutter.

In parallel, under Miku's guidance, we melted milk chocolate in a hot-water bath, carefully.

And then, on the sweet, fragrant cookies baked golden in the 170°C oven, we applied decorations with the melted chocolate, chilled them in the refrigerator until the chocolate set, and they were done.

"Thank you so much for today!"

The time was just past four. At the low table in the living room.

Raiha-chan wore a smile thoroughly blended with joy and delight.

"With these, Valentine's will go perfectly!"

"I'm glad you're happy with them. Well then, shall we dig in soon?"

Taking off her apron, Nino sat down.

On the low table were the freshly made chocolate cookies.

And on top of that, the madeleines Raiha-chan had brought as a gift.

Having finished cooking, we decided to hold a tea party.

We'd baked extra chocolate cookies for ourselves to eat, after all.

"Mm~. They could be served in a shop, no question."

Yotsuba's expression melted at the sweetness of the chocolate cookies.

I had one too.

About five centimeters in diameter. As I brought it to my lips, a deeply rich cocoa aroma tickled my nose.

The moment I set my teeth into it, a pleasant crunch.

Since they'd been in the refrigerator they weren't fresh from the oven, but the cool chill on the tip of my tongue felt good.

What filled my mouth was the mellow sweetness of cocoa.

And then the rich presence of the milk chocolate.

Those two elements harmonized beautifully, without clashing.

In other words, to put it in a word—

"It's very delicious."

If I weren't suffering from loss of appetite, I would have polished off ten of them.

Convinced of that, I savored the black tea Nino had brewed.

"The madeleines Raiha-chan gave us look delicious too, you know? There are all sorts of kinds."

It was just as Miku said.

Coffee, black tea, matcha, mandarin orange...

Madeleines of various flavors were bagged and individually portioned.

"Raiha-chan, would you like a bite?"

"Is it okay for me to have some when I'm the one who brought them?"

"Of course! Say ahh."

Yotsuba cut a small piece of an orange-flavored madeleine with her fork and brought it to Raiha-chan's mouth.

"Mm~, this is delicious too! Though it loses to the cookies we all made."

"Hehe. Thanks. I'll give you a bite of mine too."

"How about the coffee one? I'll feed it to you."

"Nino, Ichika, no fair. Let's have the matcha one too, Raiha-chan."

Being fed various madeleines by fork one after another, Raiha-chan colored her lovely face with happiness, going "Mm~!"

"Ehehe, I'm so happy. I want to share some with my big brother, too."

Too kind!

To have such a cute little sister — Uesugi-kun really has it too good.

Well, he'll be getting Valentine's chocolate from us and Raiha-chan, so let's call this happiness a portion shared with him at a later date.

I'm glad Raiha-chan was happy.

And of course, as a 'Quintuplets' Day' it was a huge success too! We managed to make a good memory.

Yotsuba's motive still wasn't clear, but...

The someone important was probably Uesugi-kun.

The reason she'd disguised herself was probably that she was embarrassed about being seen by an acquaintance while buying chocolate for Uesugi-kun.

When I thought about it that way, Yotsuba had a cute side to her too.

"Hehe."

With this, the deductions were over.

I'd managed to arrive at the answer and build momentum toward the entrance exam!

"That reminds me, Yotsuba-san. I heard from my big brother that you're going to live on your own — is that true?"

"To be precise, I'm still on the fence about it."

"Hmph. You should just hurry up and go pick out a place to move to. That'll make up your mind."

"Raiha-chan, Nino's only saying this because she's lonely, you know?"

"Miku!? You and your unnecessary comments again!"

"Ahaha, actually I went and looked at a few candidate places to move at the end of last month. Dad introduced me to a kind real-estate agent."

Huh!? The surprise leaked from my mouth and Raiha-chan's.

...The end of last month?

"Whoa, you startled me. What's wrong, you two?"

"No... Yotsuba. What day did you go to view the properties?"

"January 31st."

"Do you have proof!?"

"What's gotten into you all of a sudden!? I do, sort of."

Look, Yotsuba said, showing me her phone screen.

She must have taken them to keep a record of the viewing.

In her camera roll were any number of photos showing the interiors of properties for living alone.

The displayed shooting date was January 31st.

"It was pretty rough. There were a lot of properties to see, so it took from evening into the night."

No way!

So Yotsuba had an alibi for the time of the crime?

No — maybe the photos were fakes and this was part of a fabricated alibi too... is what I thought, but that wasn't it.

Ichika might be one thing, but given Yotsuba's personality, I couldn't imagine her crafting an alibi this elaborate.

What I recalled was Yotsuba's words: "I want to give someone delicious chocolate as a present, too."

I couldn't think those were a lie, either.

In other words, Yotsuba hadn't bought chocolate to give to Uesugi-kun.

She wasn't the culprit... she wasn't the fake Itsuki!

"You look pale, are you okay? Want me to feed you an ahh too, Itsuki?"

As I heard one of my sisters' voices offering me a madeleine—

Raiha-chan and I could only stand there in a daze.

"Let's organize the situation one more time."

After dinner, I decided to talk things over with Raiha-chan in my room.

When the tea party ended, everyone suggested Raiha-chan stay the night.

She'd nodded to it herself.

The loungewear was a little big, but I lent her some of mine.

Of course, the reason Raiha-chan had decided to stay over was that the investigation had gone back to square one.

No — the situation was even worse than square one.

"To think every single suspect would be cleared from the investigation..."

"Could it be that the culprit is one of those doppelgänger things?"

"Eh!?"

"I heard from my big brother that misfortune comes to people who see a doppelgänger..."

"S-surely not, that's not it."

"What do we do!? If our house gets any poorer we won't even be able to eat curry!"

"Raiha-chan, your personality's nothing alike, but you really are Uesugi-kun's little sister..."

Is it the family finances you're worried about, I thought, as I gave a tight squeeze to the right hand of Raiha-chan, whose face had clouded over.

I was terribly weak to the occult and ghosts and that sort of thing too.

But right now I couldn't afford to be scared.

"Let's check one more time for anything we missed! There's no mistake that you met the fake Itsuki on the evening of January 31st, right?"

"Of course! Looks-wise she was Itsuki-san through and through. I don't know where she bought it, but she was carrying a handbag with chocolate inside."

"After that the two of you ate cake at 'REVIVAL.' What the fake Itsuki ate was chocolate cake."

"...It's no good, I can't find anything we missed."

Raiha-chan was thoroughly bewildered, but that was only natural.

There wasn't anything unnatural in what she'd just told me...

"Wait a moment!"

"What's wrong?"

"No... Raiha-chan, just now you said, 'I don't know where she bought it, but she was carrying a handbag with chocolate inside,' right?"

"Yeah."

"You don't know where she bought it. Which means — could it be that the handbag the fake Itsuki was carrying didn't have a shop name printed on it?"

If so, that was strange.

When I thought about it calmly, how had Raiha-chan known the contents of the handbag were chocolate?

She'd never said anything until now about the fake Itsuki telling her.

"How did you know the contents were chocolate..."

"That's easy!"

A bit proudly, Raiha-chan told me.

The reason she'd known it was chocolate.

The mystery was solved.

Right before the exams, the most activated my thought circuits had probably ever been in my life delivered the answer.

The culprit could only be her.

The only thing I didn't understand was the phrase 'someone important.'

Just who was she planning to give the present to?

I wanted to confirm it if I could — as her sister, I absolutely couldn't leave it alone!

But as for a method to confirm it...

Back when Fuu-kun first came to this house, he tackled me to the floor right after I'd gotten out of the bath.

As I kept thinking without giving up, Nino's words from earlier that day replayed.

Along with the detailed circumstances of when Uesugi-kun had tackled Nino to the floor.

That's right — with this method—

"I might be able to confirm it."

"R-really!? You figured out the culprit, Itsuki-san!"

To blow away the anxiety of Raiha-chan, who'd asked the question, I made my decision.

To go out of my way.

"Nino! Let's take a bath together for once!"

The Nakano household's changing room.

With the sound of running shower water echoing, I called out to Nino through the bathroom door.

That's right, the culprit was — Nino.

I'd been able to deduce that when I asked Raiha-chan how she'd known the contents of the fake Itsuki's bag.

That's easy! It smelled like chocolate!

I'd been careless.

I hadn't told Raiha-chan, but Nino had bought a certain something last month.

Nino's going to the shopping mall for the brand-cosmetics New Year's sale. She said she wants something woody or gourmand.

Ichika's voice from the big cleanup came back to me.

In the end, the cosmetics Nino bought were gourmand.

Nino had told me before, but gourmand meant a perfume with a scent like vanilla or chocolate.

She'd once put some on me, saying "This might actually suit Itsuki better than me," and it had a sweet aroma just like candy.

Raiha-chan had mistaken that scent for the smell of chocolate.

If Nino had been wearing the same perfume today I would have noticed, but we were inside the house, so she wasn't wearing it.

That was exactly why the culprit could only be Nino!

"—Yotsuba? Didn't you go out for a run?"

To the voice echoing through the door, I — disguised as Yotsuba in a bob-cut wig — answered.

"Um, since Raiha-chan's staying over and all, I thought I'd want to be home, so I turned back."

"Hmm. So, why a bath with me?"

"You taught me how to make chocolate, so I thought I'd scrub your back as thanks!"

"Sure. Well, fine."

It's okay, she shouldn't have caught on, I thought, breathing a sigh of relief.

Nearsighted Nino always wore contacts, but she took them out while bathing.

Because of that, she'd once mistaken Uesugi-kun for Miku after a bath.

The result was the accident of being tackled to the floor by him.

In any case, in this situation Nino couldn't tell faces apart.

I wasn't very good at disguises, but with this I should be able to fool her.

My chest ached with guilt, but I'd snuck into Ichika's room and borrowed the wig while she was relaxing in the living room.

To avoid being recognized as a celebrity, Ichika kept several disguise items for impersonating her sisters.

Thanks to helping with the big cleanup, I'd already grasped where the wigs were stored.

And if I were to disguise myself, it had to be Yotsuba.

Yotsuba, who was self-training in preparation for entering a sports university, wouldn't be back from her run for an hour.

I had the feeling Ichika and Miku weren't the type to suggest "let's bathe together"... wait, this is bad.

When I went to take off my shirt, the wig slipped—!

"Yotsuba."

My heartbeat shot up all at once.

The bathroom door had suddenly opened.

What filled my vision was Nino's indecent figure, wet with clear water.

"...What?"

I was half-naked, somehow fixing the wig while suppressing my nerves.

Nino furrowed her thin brows with a "Hmm," and then,

"Could you grab the bath salts that are over there somewhere? I forgot to put them in."

Thank goodness, I thought she'd caught on!

Enduring so my relief wouldn't show on my face, I handed her the rose-colored bath salts that Nino liked.

Each sister had different preferences for bath additives.

Ichika liked bath milk. Nino, rose aroma. Miku, Shimobe Hot Spring⁵. Yotsuba, citrus-based.

I liked bubble baths and... no, this isn't the time to let my thoughts wander.

"I was just about to wash, so I'll leave it to you."

"Leave it to me."

A magnificent, well-balanced figure without an ounce of excess fat.

Admiring her smooth, beautiful skin, I washed Nino's back with a towel covered in suds, thinking.

Just who was this 'someone important'?

Someone she wanted to make it look like she hadn't been the one buying a present for.

...Surely she hadn't given up on Uesugi-kun and run off to a new love!?

Tormented by that anxiety, I'd had no choice but to confirm the truth through forceful means.

With me — the appetite-less me — she probably wouldn't talk out of consideration, but with another of the quintuplets it'd be different.

Nino had a taste for wild men.

I wanted to believe there was no way, but what if she'd gotten hooked by some nasty delinquent...!

"You're washing awfully gently."

"Eh, you think so?"

"You usually scrub pretty hard, right? This way of washing feels more like one of the other sisters."

This is bad!

I had to cover for it!

Here, some clumsy, Yotsuba-like behavior—!

"Nino! Want me to wash your hair too!?"

"Huh? What's gotten into you all of a sudden?"

"Now, now, don't hold back... ah, this is body soap."

"What are you doing!? You'll damage my hair! Are you trying to destroy my cuticles!?"

"U-uwaah, sorry, sorry, I'm glad I noticed before washing~."

"...You're not doing this on purpose, are you? Are you making fun of me?"

"N-n-n-no way."

Phew.

Maybe because I was nervous it came out a bit wooden, but I should have managed to cover.

Pulling myself together, let's get to the main subject.

"That reminds me, Nino? When you disguised as Itsuki last month, did you meet Raiha-chan?"

"What. You knew?"

My heartbeat shot up.

Sitting in the chair with her back to me, Nino said it lightly, as if it were nothing at all,

"I hope Itsuki's happy with it. The surprise."

"Huh?"

"Hey. What's with that reaction? We all chipped in to give Itsuki a present, didn't we? To cheer her on for the exams."

"R-right... that's right!"

Desperately capping my shock and confusion, I somehow replied.

We'd decided to give a present to me?

Then, 'someone important' was...

"Everyone worked hard, so we should have been able to pick a good one. I even went out of my way to dress up as Itsuki to check with my own eyes whether it suited her. Well, I forgot to take off the disguise and ran into the little one."

A surprise present.

That was why Nino couldn't reveal her identity to Raiha-chan.

And all of my older sisters had been involved in it.

"Ah..."

The deduction unfolded in my head.

Going by the words "everyone worked hard," maybe Ichika and the others had also each picked something out when they had free time, using the quintuplet-specific method of disguising as me.

A present that would suit me perfectly and serve as a cheer for the exam.

...I'd made an outrageous oversight.

I'd been completely convinced the culprit was acting alone.

In reality, every one of the quintuplets except me had been involved in the fake Itsuki.

In other words, all of the suspects were the culprit!

"But you still haven't given it to Itsuki, right?"

"What else could I do? Right after I bought the present, she lost her appetite. If I gave it to her now she'd feel even more pressure, and she might end up even less able to eat."

After washing her hair, Nino rinsed off the suds with the shower and then sank into the rose-colored water.

I washed my own body too.

But even my sunken heart wasn't washed clean.

I'd suspected Nino — wondered if she'd gotten hooked by a delinquent.

And the present everyone had prepared, the current me couldn't even accept it...

"You'll catch a cold, you know? Soak in the water properly."

When I felt awkward and tried to get out ahead of her, Nino called out to me.

"A bath is the best friend of beauty and health."

Urged on, I soaked in the water.

Facing Nino inside the bathtub.

Soaking in the rose-colored water, Nino somehow looked more grown-up than usual.

Her hair, glossier from soaking up the moisture, was so beautiful it made me want to touch it.

Her expression was so dignified it was hard to believe she had the same face as me.

Slender shoulders. A delicate collarbone. And the richly curved line of her chest peeking up from the water's surface was so alluring that even I, one of the quintuplets, nearly stared.

"Are you worried about something? Right now you've got an atmosphere like Itsuki."

I thought my heart would explode.

When I couldn't answer anything, Nino strung her words together.

"That girl's worrying over the exams, too."

"That's true."

"Well, even if she fails in the worst case, it's fine."

"Whaaat!?"

The shock that leaped out of me echoed through the bathroom.

Then, Nino let her sincere voice ring out.

"I wouldn't blame Itsuki even if she failed the exam. Absolutely not. She can just try again next year, and when she does, I'll... no, we'll cheer her on again. Even if you fail, as long as you don't give up, there's a chance."

"That's true, maybe you're right, Nino, but—"

"And I'm one of the people who hasn't given up, either. Not just from failing — even from a broken heart."

The instant I saw Nino's gentle smile, a past memory replayed in my head.

After last year's school festival.

After Uesugi-kun chose Yotsuba, Nino had told Yotsuba this in an empty classroom.

The contest isn't over here. I'll be watching how things go for you two from a little ways behind. The moment you show even the slightest opening, I'm going to snatch him away.

I think the feelings put into those words were split in half.

Half was the wish, as family, to push Yotsuba forward.

The other half was the love for Uesugi-kun that she hadn't been able to shake off.

"I understand it myself."

In a terribly earnest voice, Nino confessed, as if making penance.

"Even though my little sister and the person I love started dating, I still can't completely give up on this love."

"That's..."

"You could call me a super clingy, heavy woman..."

"T-that's not true."

"I'm definitely heavier than Ichika was on the school trip, heavier than Miku's long bangs, heavier than Yotsuba's training power-ankle weights, heavier than Itsuki's body weight."

"Let's stop getting depressed with such uniquely specific comparisons..."

I mean, I shouldn't be that heavy!?

I do sit-ups daily, and if anything, with my current loss of appetite I might be lighter than everyone!

"Still, right now I'm grateful for this version of myself."

"Eh?"

"If I have feelings that won't give up, then Itsuki has the same thing too. Because we're quintuplets. Even if she fails, she can recover. I think she should go into the exam with that much resolve. If she does, she'll definitely pass!"

Maybe because she was soaking in the water, her cheeks faintly dyed strawberry-red, Nino strung her words together.

"I'd never say it in front of her, but Itsuki is the little sister I'm proud of."

"D-do you really think so?"

At words far too straightforward, I found myself asking back.

Nino answered at once with a smile, "Obviously."

"You know, even during last year's school festival, that girl studied almost the whole time whenever she wasn't working the stall? Desperately holding back from wanting to play, from wanting to go around tasting all kinds of food. I think that's really admirable."

I felt my face grow hot at the too-straight confession.

C-calm down, me.

The one I'm dealing with is that Nino.

Just because I'm disguised as Yotsuba, there's no way she'd say lines any more honest and embarrassing than this to a sister...

"Itsuki works the hardest at studying out of all of us. To make her dream of becoming a teacher come true. I respect her so much I could even admire her. This is my honest truth, from the bottom of my heart."

"Ngh..."

"As proof, after I got into culinary school, I said this to Miku, you know. 'I wonder if I can become like you all.' Right now I don't have a clear dream or goal. So I wanted to be like everyone. I wanted to have my own dream, like Itsuki."

"U-um, Nino? Any more than that..."

"In that sense, I get all sorts of energy from Itsuki — I couldn't ever thank her enough. ...Well, that girl probably hasn't noticed even a tiny bit."

"It might actually be pretty obvious, you know!?"

I was really glad to be soaking in the bath! I could pass off my red face as the hot water's fault!

I mean... this isn't a dream, is it?

To think Nino felt this way about me.

This being Nino, she surely cherished her other sisters too, but... somehow, it tickled, it itched.

Deep in my chest, it was just warm.

"Still, it's not that I don't feel anxious about Itsuki right now. Because that girl looks like she's getting too desperate not to be the only one left behind."

I felt like she'd struck the core of something deep in my heart.

I'm the youngest, and I'm the only one — I didn't want to cause everyone any worry. I had to pass, no matter what. That was the first step toward independence!

That's what I'd thought before.

If I failed the university exam, I felt like I'd be the only one — the youngest — left behind.

That I wanted to become more independent so I wouldn't have to lean on my older sisters.

But those feelings were too strong, and...

"...so you lost your appetite from feeling the pressure, then."

"...then?"

"Nope!? Thanks, Nino! I'll pass along what you just told me to Itsuki!"

I decided to get out of the water ahead of her.

I wanted to take off the disguise and thank her as Nakano Itsuki, but I felt I wanted to save that.

Until the day I told her my exam results.

"I'm rooting for you. Do your best."

As I left the bathroom, Nino saw me off in a bright voice.

February 14th, Valentine's Day.

Ten in the morning, the day before the entrance exam.

Since it was an optional-attendance day, I didn't go to school and instead went to the library where I'd often studied with Uesugi-kun and everyone.

"Here, I should be able to concentrate."

February's weather was cold to exam-takers, and today's sky was gray. According to the forecast, it would even snow tomorrow.

But here it was nice and warm with the heating on.

Perhaps others had thought the same as me — about eighty percent of the seats were filled with people around my age.

Ever since the day I took a bath with Nino, my appetite had recovered a little.

Though I was still only at about sixty percent of my peak.

It would have been nice if all the pressure of the exam had disappeared, but reality wasn't that convenient.

About a year and a half of working hard with Uesugi-kun and everyone.

Because I'd be staking all of it tomorrow, in the decisive battle of a lifetime.

"Nngh."

When I sat down at an open counter seat, the pressure came rushing back.

Nino had said all that in the bath, but if I were the only one unable to decide my path...

"Your expression's stiff. Well, I suppose it's hard to be all smiles the day before an exam."

"Yeep."

Suddenly poked in the side from beside me, I let out a small noise.

When I turned to my side, there was Nino, in a school uniform just like me.

"Why are you here?"

Since it was a library, I asked in a whisper so the people around wouldn't hear.

At that, Nino let out a small sigh of "Haah" as she sat down at the counter seat.

"The culinary school I'm going to makes you fill out and submit a career-path survey before you even start. I think it's way too early, but well, it'd be no joke if they revoked my acceptance, so I figured I'd write it here."

"Nino..."

"Thanks. I'm glad you're here, Itsuki. I can concentrate best when I'm with a sister. It reminds me of when we all worked hard on our exam studies, being taught by Fuu-kun—"

Before her words could finish—

I had wrapped my arms around Nino, who was sitting beside me.

"Wha— Itsuki?"

"Ah... s-sorry!"

Coming to my senses, I pulled away from Nino's body.

W-what was I doing!

Doing something like this in front of a whole crowd of people — it wasn't like me!

It was like Raiha-chan hugging Yotsuba and the others on the day we made chocolate. Childish.

But...

"Honestly, you idiot."

After saying it in a small voice—

Nino wrapped her arms around me.

"Nino?"

"If you want to be spoiled, you should just say so honestly."

"Ugh... you're not honest yourself either, Nino."

So the people around us wouldn't hear, we exchanged words in whispers.

"You came all this way out of concern for me, didn't you? Even telling a lie about having to fill out a career-path survey before enrolling."

"What. You saw through it."

"It's as obvious as Uesugi-kun's favorite hundred-point trap."

"Ahaha. You're absolutely right. But you concentrate best when you're with a sister, right?"

"...Hehe. I can agree with those words."

Returning Nino's smile—

I had wrapped my arms back around her slender body.

I hadn't let any weakness show because I didn't want to worry everyone, but the truth was I'd been feeling the pressure of the exam the whole time.

Because of that, even a moment ago I hadn't known whether I could concentrate on studying.

But Nino had come for me.

When I thought about that, I couldn't help wanting to be spoiled.

Of course, I'm sure Nino was embarrassed too.

After all, she was being clung to by her little sister in a public place.

"Honestly, what a spoiled baby you are."

Even so, she smiled while sitting in her chair and gave my body a squeeze.

Nino's body warmth, her breathing, her heartbeat — they came through to me.

"———"

Warm.

Thanks to Nino holding me, I could forget the pressure of the exam for the first time in a while.

That's right — my heart felt lighter than it ever had.

Grrrrrrrooooowwwwwl~~~~~.

"Hm?"

That sound just now.

Surely...

"Itsuki, you..."

Nino, with a terribly surprised expression.

After a few seconds of silence filled the space between us, the "grrrowl~" sound rang out again.

From my stomach.

"Wha— Nino!"

Ignoring my confusion, Nino crammed my study supplies into her own bag.

Rising from her seat, she swished the pleats of her uniform skirt and pulled me by the hand out of the library.

"Where are we going!"

"The break room! The break room here was okay for eating and drinking, right? Then we're eating! Itsuki, you're hungry, aren't you!?"

I haven't heard it in two weeks — that noisy stomach of yours! Nino shouted, her face filled with delight.

It was true that my stomach had been as silent as a dying prisoner lately.

But now, as if it had come back to life, it was howling magnificently.

Give me the reward for all that long entrance-exam studying, right now! it demanded.

"Wait a moment! Even so, why eat now?"

"Isn't it obvious. Right now there's something more important than studying. The exam is a full-day battle of stamina. Eat even a little and get your stamina and willpower back."

"Am I a boxer who's finished cutting weight before a match!?"

"Same thing! Tomorrow, go beat the exam questions to a pulp and win by KO!"

"S-so violent! Besides, they don't sell any food here—"

"No need to worry!"

Nino, having opened the door to the library's break room, immediately began her preparations.

Sitting at a table, she took lunch boxes out of her tote bag.

And what's more, two of them.

"I made lunch. Yours too, Itsuki."

"Eh!?"

"You can eat my share too, you know? Refuel before your stomach bug starts another strike!"

After smiling brightly, Nino opened the lid of a lunch box.

Packed inside was shining germ-rice.

A rolled omelet with the faintly sweet aroma of dashi.

An elaborate potato salad with finely cut apple in it.

Bright-red fruit tomatoes.

And — wonder of wonders — piping-hot miso soup in a thermos.

On top of that, perhaps as a good-luck charm to triumph over the exam, a thick tonkatsu⁶clad in golden batter... amazing! Truly a hundred-point lunch!

What a fragrant aroma it was, tickling my nose!

"Think you can eat?"

"Of course! But there's a problem."

"A problem?"

"It looks so delicious that my stomach's potential has been drawn out to its limit. My current appetite is at its peak... no! It's in a state where it can unleash even more power than that!"

"Stop dropping bombshells that could lead to a Nakano household food crisis."

"Ngh... I'm not sure even two lunches can satisfy this hunger..."

"Honestly, what am I going to do with you. In that case, I'll give you this too."

"Eh?"

To a confused me, Nino held out a beautifully wrapped box.

And then, with her cheeks coloring just a little,

"From me to you — Happy Valentine's."

She smiled bashfully, looking embarrassed.

"Inside are the same chocolate cookies as before. You couldn't really eat your fill that time, right, Itsuki?"

What she handed me on Valentine's Day itself was the finest dessert.

Faced with the feast, my stomach again let out a cheer of "grrrowl~~~."

"...Hey. Honestly, getting thanked by your stomach is kind of a turn-off, you know?"

"I-I can't help it! My stomach's happy too!"

"Pft, ahaha! What's that supposed to mean."

"Ehehe. Don't laugh. But, um... Nino."

"What."

"...Thank you. Let's eat!"

After conveying my thanks in my own voice too, I reached out with my chopsticks.

The food that had always supported the quintuplets.

The seasoning I was most used to.

The lunch and chocolate Nino had worked hard to make tasted so reassuring it made me smile without thinking.

"Once more! Congratulations on getting into college——!"

A few days later.

A party was being held in the gorgeously decorated living room of the Nakano household.

Nakano Itsuki's college-acceptance celebration.

Thanks to eating lots of Nino's cooking the day before the exam, I'd gone into the test with my willpower and stamina full, and I'd been able to give it my all.

And on the night before the exam, everyone other than Nino had given me presents too.

Valentine's chocolate to refuel my energy during breaks.

And, a warm muffler that wouldn't lose to the cold of the powdery snow spilling from the sky on exam day.

That's right — the surprise present Nino had told my disguised self about!

"Once more, thank you all! Thanks to that muffler I didn't get cold on exam day either!"

The relief and delight of finally being freed from exams rode through my whole body on my bloodstream.

Since then my appetite had fully recovered, too.

And on top of that, the party's menu was my absolute favorite, home-style yakiniku.

The cuts of meat sizzling away on the black hot plate.

Hello. We meet again. How many times have I dreamed of this moment.

Rest assured.

Tonight's M・A・Y Detective, who'd solved the fake-Itsuki case, the loss of appetite, and even the exam, had no openings!

I would not commit the folly of setting down my chopsticks early!?

"More rice, please."

"How many bowls of rice is that for you today?"

"I'm really glad, the usual Itsuki is back."

"Um, Miku? It feels like more than just 'back.' Maybe we really should take her to the hospital?"

Touching her smooth short hair with her fingers, Ichika looked confused.

"Itsuki-chan, since the exam ended, the amount you eat has gone up to about 1.3 times last year's."

"There's no need to worry. I'm holding myself to eighty percent full."

"That's eighty percent!? You've been eating katsudon for breakfast twice a week lately, right? This isn't Itsuki, it's the Nakano household's mega-calorie monster!"

"It's fine, Yotsuba. Right now she's making up for the calories she wasn't getting."

"Nino..."

"The Meat-Bun Ghost makes a grand comeback!"

"That nickname is violence to me, so I'd appreciate it if you'd stop!"

"Ehehe. With it this lively, it would've been nice if Uesugi-san and Raiha-chan could've come too."

"Nothing to be done. Fuutarou passed too, so the whole family's eating out."

"And we don't want to intrude on a happy family celebration."

Just as Ichika said, Uesugi-kun had also safely gotten into a university in Tokyo.

I gave him chocolate the other day, come to think of it. As nourishment heading into his exam.

Thanks. It's a lot, sure, but I'll finish all of it.

He'd said that, so he probably got Happy Valentine's from Ichika, Nino, Miku, and Yotsuba too.

"Hm?"

Just then, an email arrived on my phone.

The sender was Uesugi-kun.

That reminded me — I'd sent him a congratulations email a little earlier.

Knowing Uesugi-kun, I'd been so sure he'd ask something like, "My tutoring's almost over, so you don't know any decent-paying short-term part-time jobs I could do over spring break, do you!?" but—

[Sorry for going out of your way to congratulate me. Good work on your exams too.

All five of you have your paths decided now — that's a relief.

Knowing you, Itsuki, you'll probably get all modest and say something like 'it's all thanks to everyone,' so I'll say this: the number-one reason you passed isn't because someone helped you.

It's thanks to you.

It's the result of the effort and ability you built up yourself.

That said — and this goes for me too — deciding where you'll go to school isn't the goal. It's a new start.

Keep working hard to make your dream come true. All five of you.

Don't worry.

You all can definitely do it.

Once more, congratulations on passing.]

At a message far too much of an ambush.

The emotions I'd stored deep in my chest nearly overflowed.

"Itsuki-chan, something wrong?"

"N-no, it's nothing."

Feeling my eyes mist over with happiness, I covered it up with a smile.

...It's like a dream.

To think Uesugi-kun would send me an email like this... hehe.

Maybe Mr. No-Delicacy has grown up just a tiny bit!

Well, it seemed pretty likely that Raiha-chan had warned him, "You have to congratulate her too, big brother. And think about what you write properly!" and being a tutor, the wording was a bit lesson-like, but...

[Thanks for the congratulations!

It's still a bit early, but thank you so much for being our tutor this past year and a half.

I'm happy you said my passing was thanks to me, but I'm going to say this anyway, okay?

I was able to pass thanks to everyone.

Ichika. Nino. Miku. Yotsuba. And, Uesugi-kun.

Because you taught me, I was able to solve the exam questions.

And so we can walk toward our own dreams.

I'll pass along the words everyone gave me in their emails, too.

Just like you said, I'll work hard in college too, okay?

So that I can become a teacher — like my ideal, my mom, and you.

Uesugi-kun, do your best in college life too!]

I sent the email in casual speech, not polite speech.

Maybe because my feelings ran high, the wording came out a little embarrassing... but that's not my fault.

White Day⁷is still a ways off, and yet Uesugi-kun's the one who sent an email like that, you know?

"Itsuki, you look kind of happy."

What are you looking at? Yotsuba tried to peek at my phone, so I hurriedly hid it.

Hehe, even from Yotsuba, I can't show this.

I'll pass along Uesugi-kun's encouragement to everyone, but this email I'll let myself keep just for me.

"By the way, it'll be late at night, but Dad says he's coming too."

A little while after the yakiniku ended.

Slicing up the strawberry cake for dessert, Nino said happily.

"Really? I'm so glad. I'm getting hungry again."

"All right! Just become a dog of appetite! When your diet phase comes around, I'll keep you company!"

"I thought the cake Nino and I made might be too big, but with Itsuki here it should be fine. I ate a lot of yakiniku so I'll have a little... oh, right."

Miku, smiling, cut a small piece of the cake on her own plate with her fork.

"Have a bit of my share? Say ahh."

"Honestly, Miku~. Itsuki hates being treated like a child—"

"Don't mind if I do."

When I popped the cake she'd held out without hesitation into my mouth, my older sisters other than Nino were surprised.

After fully savoring the sweetness of the shortcake, I smiled brightly,

"Thank you very much."

"Y-you're welcome."

Satisfied with Miku's embarrassed reaction, I made another request, still smiling.

"Ichika's too, please."

"Huh? U-uh, sure."

"Thank you very much. Now then, Yotsuba too. Will you feed me?"

"Whaa!? Somehow that's kind of embarrassing."

"...No?"

When I imitated Raiha-chan on a whim, it was a critical hit.

Yotsuba, blushing all the way to her forehead, brought the cake to my mouth.

"Ehehe. Thank you, Yotsuba."

"This is bad!? Itsuki! Itsuki's too cute! Even if I have to fabricate a backstory where we're actually sisters who got separated as little kids, I want to make her my little sister!"

"She's your little sister to begin with... And Itsuki, what's gotten into you?"

"I thought acting spoiled like a child once in a while might be nice."

Before the exam, I'd hated being treated like a child.

Because I wanted to walk the path to independence so I wouldn't be left behind by my older sisters.

When I think about it now, that very idea was childish, wasn't it?

"It's precisely by daring to acknowledge the childishness left inside yourself that you're an adult."

"Oh, Itsuki-chan's an adult!"

"There are still plenty of childish parts to her, though. But when we took a bath together, I thought she was an adult."

"...So you'd noticed after all."

The night of the 9th.

The words "I'm rooting for you, do your best" that she'd given my disguised self must have been encouragement not for Yotsuba, but for Nakano Itsuki.

"When did you notice? Was it after all when I said 'so you lost your appetite, then'?"

"Nope. It was when you handed me the bath salts in the changing room."

"Already at that point!? Even though you didn't have your contacts in..."

"Idiot. Of course I'd notice right away."

I couldn't help being impressed.

To think she'd seen through my act even with poor eyesight.

"Because your underwear was different from Yotsuba's."

To a me who went blank with a "Huh?"

Nino spoke proudly, like a great detective who'd nailed down the culprit.

"When I saw your figure in the changing room, I noticed. Even without contacts, I could tell the difference in underwear, at least."

"Ngh."

"At first I thought it was Ichika, but I reconsidered that you were Itsuki in disguise. You were sneaking around with the little one during the chocolate-making, too."

As if teasing.

Nino curled her fair cheeks into a grin.

"Unlike Yotsuba's kiddie panties, you were wearing surprisingly grown-up ones, Itsuki."

"Nino!?"

While feeling the temperature of my face climb higher and higher, I remembered.

...That's right.

As thanks for doing the big room cleanup at New Year's, I'd received them from Ichika.

To be exact, it was a brand-new lingerie set.

A sexy design, the kind Ichika wore. The color was, of course, black.

Ichika had joked, "The exam is the decisive battle of a lifetime! You need lucky underwear, right? Besides, you're going to be a college student, so this much is totally normal!"

She'd probably cheered me on with a typical Ichika joke, trying to ease her little sister's nerves even a little.

And I, thinking "she went to the trouble of giving them to me," wore them on exam day too.

And, come to think of it, I was wearing them the night I took a bath with Nino, too—!

"Itsuki, you really are an adult."

"Niiino!"

I shouted, wanting to cover up the shame scorching my whole body.

T-this is so unfair!?

Like this, I can't even look at Nino's face!

At the very, very end, the detective had become the tragic victim!

Having my underwear from Ichika seen was one thing, but when I remembered the words Nino had given me that night, my face grew even hotter.

I'd never say it in front of her, but Itsuki is the little sister I'm proud of.

The fact that she'd noticed the disguise from the very beginning meant—

That had been precisely encouragement for me myself.

And the words she'd spoken after that, all of them, had been to give me courage...!

"Hehe. If you still intend to shout, I'll cover your mouth, you know?"

To a me whose face — no, even my ear tips — had grown feverish with embarrassment and happiness, she held out a piece of shortcake stuck on her fork.

Her cheeks faintly colored strawberry-red, Nino wore a somewhat bashful smile.