The enemy's attack had been fast and covert. Ma En had to concede that at least some of what the Room 3 neighbor had raved about made sense. Only by hiding within an ordinary social circle — using daily contact as the vector — could someone have gotten to him without triggering any alarm at all.

Furthermore: he'd been in Japan for only two or three days when it happened. The number of people he could have encountered in that window was limited. If he eliminated passing strangers and restricted the pool to people he'd actually spoken with — or narrowed further, to people he'd dealt with formally, more than once — the list became very short.

No matter how much he didn't want to, given the absence of hard memory, Ma En had no choice but to include Hirota-san. Even narrowing the suspect pool to its absolute minimum, his recently acquired girlfriend met every single criterion for the attacker.

And yet suspecting Hirota-san was, for Ma En, a quietly painful thing. He replayed their time together in his mind — her expressions, her laughter, her warmth — and found nothing wrong. Not a single false note.

The only thing that pointed to her was the Room 3 neighbor's intense, visceral aversion — that look of having seen something terrifying. But the Room 3 neighbor's own mental state was hardly a reliable baseline.

Whether Hirota-san actually had a problem — on a personal level, Ma En hoped desperately that the culprit was not someone this close to him. But this was no longer about what he hoped. A situation involving 100,000 people was not something he could afford to set aside for the sake of his feelings.

Of course, among the people he still remembered, the suspects weren't limited to Hirota Masami. Even the Room 3 neighbor himself, and Kamishima Kousuke — a fellow Party member — both had the opportunity to set a trap.

Ma En was inclined, as a rule, to take people's demonstrations of goodwill at face value. But the attack on him was a confirmed fact. His years at the postal service had taught him that you couldn't rely on apparent goodwill or apparent hostility to sort friends from enemies. A seemingly kind gesture might be an illusion. A seemingly hostile act might have nothing to do with the case.

No matter how he turned it over, the suspect pool wouldn't narrow further. He couldn't pin it to a specific handful.

The core obstacle was the lost memory. Apart from the Room 3 neighbor, no one in his daily orbit had shown the slightest irregularity. The enemy was like a character from a detective novel — an exceptionally poised killer who either concealed their crime with superb emotional intelligence, or genuinely didn't know they'd committed one.

Whether in fiction or in real criminal cases, a perpetrator who was unaware they'd committed a crime — or who had deceived themselves into complete composure — was invariably among the hardest to identify. Whether the act was deliberate or unwitting, finding cracks in their behavior was extraordinarily difficult.

This, Ma En felt, was precisely the kind of case he was dealing with.

On the other hand, he knew from experience that the more people were involved in a coordinated crime, the fewer novel methods were available to them. Coordination wasn't easy. Without veterans who'd trained extensively and practiced multiple times, adding bodies actually degraded operational integrity. Large groups typically relied on crude, numbers-based misdirection.

Could the organization the Room 3 neighbor described move with military precision? Ma En doubted it. The man had claimed 100,000. Many of those had to be ordinary civilians living ordinary lives — rice, oil, soy sauce, vinegar.

And that was the paradox: to orchestrate a crowd of people around a single target without the target noticing — and without even the participants themselves being aware — could ordinary civilians really pull that off? When they acted contrary to their daily habits, the resulting dissonance had to produce inconsistencies. Could those inconsistencies truly escape the trained perceptions of someone like him?

If it were that easy, what was the point of professionals?

So Ma En leaned toward the conclusion that the actual attack had been carried out by a specialized cadre within the larger group — people with training, technique, and operational experience. Their skill level meant their standing in the organization was not low.

But this raised a new question: how had people of this caliber managed to compromise him without his awareness? Ma En refused to believe that such operatives carried no detectable trace of their nature.

Hirota Masami was precisely the kind of person who carried no trace of specialized training. If she truly was the culprit, then she'd almost certainly acted without knowing she was being used.

Ma En was more inclined to think Hirota-san had been weaponized. A group of trained specialists hadn't attacked him directly — they'd gone through her instead.

She hadn't done anything unusual. The methods that could be embedded in daily routine were few. The likeliest was drugs. Being dosed by an intimate partner without your knowledge was almost impossible to defend against.

In the food? In the water? In the pillow? The incense in the room? Surely not her own perfume?

Could it be that conspicuously distinctive mixed-vegetable dish?

Ma En rubbed his temples. Any drug potent enough to compromise him without detection — Hirota-san, handling it with her own hands, would surely have felt something too. The odds of her being completely unaffected were slim.

And he'd need an excuse that she could accept. If he continued in close contact with her, the enemy would certainly continue the dosage. Just eating her cooking, drinking the water, breathing the air in her room or the scent on her skin — any of it might be affecting him.

The influence, beyond the initial attack, had to be ongoing — gradual, cumulative, eroding memory and reasoning like water wearing at stone. The enemy needed him functional until August; they wouldn't destroy a Room 4 tenant's mind all at once. He'd only just recovered some clarity, and he had no confidence he could maintain it under sustained exposure.

And he didn't know what had triggered the recovery in the first place — just as he didn't know what substance was being used against him.

Other questions nagged. The people behind the Room 4 Ghost Story — did they always attack in the first few days after a new tenant moved in? Or did they adjust their timing based on the individual?

If the enemy's playbook was rigid, their organization was likely plagued by internal problems. Behavioral rigidity over an extended period usually pointed to ideological ossification and structural bloat.

If the enemy was flexible, that implied a highly efficient system — or, as the Room 3 neighbor claimed, a single decisive core capable of mobilizing the whole apparatus at a word. If this was a cult, it wasn't an ordinary one.

And if Matsuzaemon was merely a demoted Superintendent, what gave him the efficiency to run a background check on a foreign national within two or three days of arrival?

Matsuzaemon had to have deeper political connections and vastly more personal power than his current rank suggested. Katsura Masakazu had hinted at the man's stubbornness, bias, self-interest, and inability to criticize himself. Ma En suspected a hidden oligarch. But the details were beyond what Katsura-sensei could provide.

"Yes, this is Ma En." He called a Kanagawa real estate agent from a phone booth, inquiring about property sales and rentals — playing the interested buyer with practiced ease while keeping his peripheral vision sweeping the area. From the apartment to the school, around the school, and now to the station entrance — he'd been thinking and observing simultaneously. Every person who passed him, every corner that might conceal a watcher, had revealed nothing he could call abnormal.

He was close to abandoning this fruitless exercise and focusing solely on the narrowed suspect list. But the Room 3 neighbor's words kept circling in his ears.

"You can't escape!"

"They're everywhere — right here!"

"100,000!"

Every time he let his guard slip even slightly, the feeling returned — eyes on him, from somewhere he couldn't locate. He trusted his instincts. All this time observing, and nothing to show for it; if the enemy was truly this invisible, the pressure was immense.

Maybe the neighbor's words got to me.

But telling himself that didn't help. When the sensation came, he couldn't simply ignore it. He wondered: if the previous Room 4 tenants had gone through the same thing, they might have been driven mad before they died.

He hung up, pushed open the phone booth door, and merged into the crowd funneling toward the station entrance. The mass of bodies didn't make him feel hidden. If anything, the sense of surveillance sharpened. He made eye contact with several passersby; their expressions were natural, their glances the ordinary kind — a normal look, an everyday moment of mutual acknowledgment.

Ma En intended to take the train out of the Tokyo Metropolitan Area. Going to Kanagawa would project the impression that he was fleeing the whirlpool. Bunkyo District was large, but it was still just one administrative ward within greater Tokyo. If the enemy had the reach to operate across such a vast area, their influence had certainly spread into other prefectures.

"You can't escape" — what does that actually mean? Making it unthinkable to run? Or crushing any attempt the moment it starts?

He wanted the enemy to show itself more directly. To come at him again, in a way he could see.

By this point, he'd already submitted his leave request.

He thought back to his confrontation with Katsura Masakazu and could only manage an internal grimace. Katsura-sensei was not Kamishima Kousuke, was not one of his old postal service superiors. The man's perspective was that of a school administrator — an educator and a businessman — and on both professional and personal grounds, he was thoroughly displeased with Ma En's behavior.

Ma En had his reasons for abandoning his post and committing this absurdity, but to Katsura-sensei, none of those reasons held water. As the Director had said: the moment Ma En left his old job and entered the school, he became a teacher. What he was doing now was not a teacher's work.

Still, despite his displeasure, Katsura-sensei had signed the leave form.

"How many days? What about your classes? You're just walking out?" Katsura Masakazu had sat behind his large desk, pen already in hand, firing the questions before Ma En could sit down.

"Three days. I need to verify some things." Ma En didn't mention the Room 4 Ghost Story. Katsura-sensei had established the school in Bunkyo District for the locational advantages; he wasn't a local and likely knew nothing of the ghost story, let alone the severity of what lurked behind it.

In fairness, if this cult was only accumulating members and had no darker scheme in play, the situation wouldn't be dire. Apart from a few tenant deaths spread over many years — serious crimes, yes — it wouldn't constitute a threat to social order.

Even so, Ma En was one of the people slated to die. Before shouldering responsibility for Bunkyo District's stability, he had to take responsibility for his own survival.

For anyone else, an exit might exist. But for a Room 4 tenant, there was essentially no way out.

He'd moved in for the sake of the bizarre. He had no one to blame.

"Three days?" Katsura Masakazu had looked up from the paperwork and fixed him with a hard stare. Ma En caught a flash of resignation in the man's eyes — there and gone — before Katsura spoke: "Fine. Three days. After that, if you pull this again, you can resign. My school doesn't need an irresponsible teacher."

"I thought you wouldn't give me even that much."

Katsura Masakazu had paused, then said — without responding to the remark — "Whatever you're planning to do, you should understand: Matsuzaemon-san has only ever expressed extreme political opinions. He has committed no crimes. Everyone is entitled to their political views. Without evidence of criminal conduct, speech alone cannot be grounds for prosecution — and no one can act against him on the presumption that he will commit a crime. Ma En-san, if you actually do something to him, you will be the criminal."

"I understand that."

"But you're saying this because you find him suspicious?"

"...I didn't say anything. You said it yourself, Katsura-sensei."

Katsura Masakazu had answered with a flat silence.

On the way to the station, Ma En made several additional preparations. Among them: deliberately leaving his briefcase behind, and recording — in coded language, on paper slipped inside it — his current thinking, the intelligence he'd gathered and suspected he might lose, and the names he'd identified as critical.

He didn't know how long his clarity would last. He didn't know when the enemy would strike again, or whether he'd lose his memory a second time. These measures were simply an attempt to hold on to whatever he could. If the enemy couldn't completely erase and rewrite his memory — if he retained even fragments related to these preparations — he'd be able to reconstruct his situation and reset his reasoning from the trail he'd left.

But if the enemy had been watching him the entire time, he couldn't guarantee these preparations would escape their notice. To compensate, he used conspicuous actions to mask subtle ones, and mildly suspicious behavior to cover the truly covert moves beneath. These were postal service methods, deployed now in a foreign country where he was utterly alone. Whether any of it would work, he honestly wasn't sure.

The enemy's stealth and technique had already gotten him once without his awareness. And even now, alert as he was, he couldn't catch so much as a tail. In practical terms, the enemy was likely more skilled, more subtle, and more capable than he was. If there wasn't something genuinely bizarre among them, then there was certainly genius.

What he was feeling now reminded him of playing games against the brilliant people at the postal service — he didn't necessarily lose, but the stakes were higher.

He joined the crowd flowing through the station, passed the ticket gates, and found a corner on the platform where he could put his back against a pillar. From this angle, if anyone in the crowd kept looking his way — whether one at a time or in clusters of three or five — he'd be able to see it clearly. He'd be able to tell whether they were looking by habit or by design.

The psychology of waiting crowds on platforms — what constituted normal behavior, what constituted suspicious — had always been a subject of active research.

Station staff and ordinary passengers alike were all observation targets.

But what actually startled him was none of these people. Before the train arrived, a familiar figure emerged from the crowd. She looked around briefly, spotted Ma En immediately, and walked straight toward his corner without hesitation.

Someone who should not have been here.

"Hirota-san?" Ma En's eyes widened. He watched her approach — dressed smartly, handbag over one arm, carrying a second bag in her other hand.

It was the briefcase he'd deliberately left behind.

"Ma En-san." She waved, half-jogging toward him.

Why? Why is she here?

"Ma En-san, I knew you'd be here." Hirota Masami seemed entirely unaware of his internal turmoil. She wore the same cheerful smile as always and spoke in that soft, warm voice: "You dropped your briefcase."

"...Why? Masami, why are you here?" He gripped her shoulders, harder than he'd intended.

Hirota Masami looked up at him, seemingly puzzled by the question.

"I saw the briefcase by the planter outside the station. I recognized it right away — picked it up, and sure enough, it was yours." She said this as though it were the simplest thing in the world. "Then I asked around nearby, and someone told me you'd already gone into the station."

A chill crawled up Ma En's spine. He released his hands, which had gone stiff. He could not treat this as coincidence.

"What's wrong? Did I come at a bad time?" She'd sensed something was off.

"No." Ma En drew a deep breath. His composure reassembled itself; the smile returned to his face. "You're a lifesaver, Masami. I hadn't even realized I'd lost the bag — there are important documents inside. If they'd gone missing, the whole trip would've been pointless."

"Is that so? How careless of you." She tapped his forehead lightly with one finger. "So even you can be this absent-minded."

"Who told you I was in here? That was very attentive of them." He kept his voice warm.

"Someone I didn't know. Sitting by the planter. He wasn't kind enough to bring it in for you, though."

Confirmed.

Ma En took the briefcase from her hands. Inwardly, his blood ran cold.

Hirota Masami's arrival carried an unmistakable signal, but Ma En recovered and fell back into their usual rhythm — smiling, chatting, easy. A few minutes later the platform speakers announced an approaching train. The placid crowd stirred into motion. Hirota Masami walked Ma En back to the boarding line and held his arm tightly — two people who didn't want to say goodbye.

When the train pulled in and Ma En stepped aboard, he could still see her through the window: standing just beyond the boarding line, waving now and then, but mostly just standing there with that gentle smile, watching the glass as though her gaze intended to follow the train all the way to Kanagawa.

An ordinary farewell. Under ordinary circumstances.

But now it raised every hair on Ma En's body. He genuinely could not fathom what was going through Hirota Masami's mind. Standing there outside the window, she looked less like a person and more like a ghost.

No — it's probably just my imagination. She's being used. That's all.

He told himself this, found a seat, and sat down.