[My name is Kamiki. Full name, Kamiki Atsuko. Yes, the thirteenth child of the Kamiki family this generation—a very ordinary, unremarkable name. But I'm used to it. It doesn't bother me.]
[Though my name is plain, I'm much smarter than the other dozen or so children in my family. What they couldn't understand, I could. What they struggled with, I mastered. So, I became the only one in my family to attend university, then advanced further, eventually becoming a researcher at a national institute. The Kamiki family was originally just a minor clan from the countryside, but because of me, our reputation has grown. Some even call me the family's lucky star.]
[Heh. There are even those who say, "If only she were a boy." Hmph. Women aren't inferior to you.]
[That said, I've only just joined the national research institute. Most of my achievements so far have been assisting established professors. I'm still far from being truly independent. That's why I must seize this [Hayarigi Elementary] project. It's a major assignment directly commissioned by the military—apparently crucial for the [Greater East Asia Co-Prosperity Sphere].]
[Or so I thought. But the project is just… studying a bunch of elementary school kids? What is the military thinking? Did someone set me up?]
[Regardless, I'll keep a daily research log. Even if the project is suspicious, my attitude must remain professional.]
[—Day 1]
[For an entire week, the other researchers and I observed these children—how they attended class, what they whispered about, every little action in their daily lives.]
[Am I really here for research? Or was I abandoned here on purpose? Am I just a glorified babysitter now?]
[And the project leader, that guy Satou… He doesn't even have a formal position, does he? Some unknown suddenly becomes my superior…]
[I don't get it. I really don't.]
[To make things worse, the researchers are split into multiple teams and forbidden from communicating. What's the point?]
[If not for the order to stay for at least three months, I'd leave immediately. Three whole months under Satou… I don't know if I can endure it.]
[Speaking of which, this school's rules are bizarre. Parents must confirm facial features when picking up their kids? If you're still in the naptime room when the bell rings, you have to stay the whole day… What's the purpose of this?]
[—Day 8]
[I've been in this research group for over three weeks now—half a month.]
[In that time, I've practically become an elementary school teacher, constantly interacting with children, occasionally teaching, but mostly hiding in the observation room, watching their every move.]
[I still don't understand the point of this experiment. I don't even know what I'm researching—no clear objectives or plans have been communicated to me.]
[Unless… I'm not a researcher. I'm part of the experiment. That's why I'm not being told everything.]
[Whatever. At this point, it's probably just some social experiment. My job is to do my part, then leave after three months. The rest isn't my concern.]
[Though, these kids are oddly obsessed with ghost stories and urban legends. At their age, I never thought about such things. Is another research team feeding them these ideas?]
[This whole experiment feels more like a farce by the day.]
[—Day 22]
[A student has gone missing.]
[I didn't know him well—just an ordinary, unremarkable boy.]
[No parents came asking. No police report was filed—because his entire family vanished too.]
[I only learned about it when he'd been absent for three days. A neighbor called the police, and when they entered the house… no one was there. Shoes neatly lined up at the entrance, but not a single trace of the family.]
**[I don't know what happened, and I didn't want to care. But the children… they seemed to already know. They said the boy and his family were taken by [Kurokuro], a monster called [Kurokuro].]
[What nonsense is this? And why do the kids sound so certain? Did someone teach them this?]
[Is another research team behind it? And that missing boy…]
[Never mind. Not my problem. I'll just focus on myself.]
[—Day 41]
**[More and more children are talking about [Kurokuro].]
[They firmly believe this monster hides in dark, cramped, or easily overlooked places—under beds, inside closets, outside windows.]
[They say those who see [Kurokuro] don't realize it at first. They forget, only noticing gaps in their memories later.]
[They say the chosen ones gain secret friends—friends that are actually [Kurokuro] in disguise—and these friends eventually take them away.]
[It should just be a baseless ghost story.]
[But more and more children believe it. Even some adults—parents—are starting to think it's real.]
[Something's not right. I hope it doesn't affect me.]
[—Day 63]
[I saw it.]
[A black thing, made of tangled lines.]
[It was crouching under a bed in the naptime room. I bent down and saw it. I'm not sure if it saw me. Then, in a blink, it was gone.]
[The research team held a small meeting tonight. Everyone was excited, cheering.]
[That unstable thing—appearing for just a moment before vanishing—was the [Hayarigi Research Group's] target. Even as a barely formed shadow, its appearance meant progress.]
[The next phase of research is starting.]
[Because I saw it, I can't leave the group anymore.]
[I have a bad feeling.]
[I asked Satou about the missing boy and his family. I hoped they were fine, but Satou just said, "They served the Empire." I'm starting to realize worse things are coming.]
[—Day 88]
[Everyone's busy now. I can't slack off like before. Logs will be shorter.]
[Hayarigi Elementary has expanded enrollment. Originally, there were only thirty-some test subjects. Now, over a hundred children—and their families—are part of the experiment.]
[—Day 92]
[The drug plan was approved. Pipes will be installed to deliver anesthetic gas to specific rooms. Some food will also be laced. Supposedly, this is for better control.]
[Many of these drugs permanently damage the mind. Some are addictive.]
[Not my problem. I'll just do my job. Everyone else is doing it. No need to stand out.]
[—Day 105]
[I talked with a researcher from another team during lunch. Apparently, Satou survived some horrific place and brought back something unbelievable. The [Hayarigi Research Group's] project relies on that thing. Another one was taken to [Yoruyama Middle School], while [Fujika Academy] is the control group without it.]
[Hard to tell what's true, but I've seen those black things multiple times now—like childish scribbles, ridiculous yet terrifying.]
[Over a dozen children have vanished.]
[But I'm relieved. One of the rules we embedded is that [Kurokuro] cannot harm teachers and must flee from them. So only students and their families disappear. Never me.]
[I'm starting to feel like a monster.]
[—Day 168]
[More than fifty children—and their families—have been "consumed."]
[It's getting hard to cover up. The military is dissatisfied. They think [Kurokuro] kills too slowly, its rules too convoluted, too easy to detect. So we're relocating, trying to add new rules—making ordinary people ignore [Kurokuro's] actions. Ideally, only the test subjects (the children) and us ("teachers") would notice.]
[The surviving students are being "transferred"—to our new research facility. The military won't let them escape.]
[The military's end goal seems to be a weapon deployable behind enemy lines—something unstoppable, destructive. Not my concern, but… how would they even control such a thing? I doubt it'll work.]
[—Day 250]
[I've been here over a year now.]
[If I've learned anything, it's how to be ruthless.]
[But it doesn't matter anymore. I just want to endure and leave. Nothing else concerns me.]
[—Day 366]
[I forgot I kept this journal. My last entry was six months ago. I've grown lazy, but what's even worth recording here?]
[Research has stalled. We wanted [Kurokuro] to be "formless," but children's imaginations are hard to control. It's settled into three fixed forms now. As we refined its rules, modifying them became nearly impossible. It's now a mechanical monster bound to [Shirasawa Elementary] and the students' homes, only harming those who understand and believe in it. Practically useless as a weapon.]
[To fix this, we'd have to start over. But we've invested too much. There's no turning back.]
[—Day 476]
[Yoruyama Middle School produced results—reportedly killed over a hundred American soldiers.]
[Pressure from above is mounting. Satou's solution? Expand enrollment. Increase the number of children (the cognitive anchors) to destabilize [Kurokuro's] rules and modify them.]
[This is reckless. [Hayarigi Research] is understaffed. Monitoring every child's words and actions is impossible with more subjects. If the kids develop unobserved impressions of [Kurokuro], what then?]
[I have to object. A weapon this dangerous, mishandled, could kill us all.]
[—Day 708]
[Satou finalized the new enrollment: 200 children.]
[Two hundred kids. Two hundred families. Researchers? Less than fifty, with twenty being administrators (including Satou). Half the remaining researchers have other duties, leaving barely a dozen to monitor everything.]
[A dozen people tracking two hundred children and their families, documenting every word they say? Impossible.]
[—Day 709]
[The military denied our request for more personnel. They claim the front lines are desperate, yet boast about sinking America's Enterprise and winning the war. If we're doing so well, why can't they spare anyone?]
[Satou approved the plan anyway. He says it's do or die now. Damn it, I don't want to die here!]
[—Day 723]
[As expected, chaos erupted immediately. We can't control these students.]
[Satou built a kennel on the first floor and hired a dog meat enthusiast as an assistant. He plans to use brutal, visceral methods to reshape [Kurokuro's] nature—making it more aggressive, more "military-approved."]
[As for me, still trapped here… I don't think I'll be leaving alive.]
[—Day 759]
[Another student vanished. No monitoring records. Something's wrong. Why don't we have data on this child?]
[—Day 898]
[Over ten students missing. Their disappearances don't follow the usual patterns. We can't figure out why.]
[—Day 9■■■■ (Records grow illegible)]
[Satou locked■■a suspect■■child■■orphan■■selected■■(text further obscured)]
[■■■mistake■■■]
[■■■over■■■]
[■■■you■■■see?]
[I■■■can't■■■leave■■■]
[But maybe■■■I can■■■become■■■friend]
[Or perhaps■■■I was always your friend■■■you just forgot■■■]
[My name is Kamiki Atsuko. I am a teacher at Hayarigi Elementary. I am your friend. Do you remember? You never forgot me, did you?]
[Yes, yes, we've always lived here, haven't we? Remember when we ate in the cafeteria? I told you about the boy in my class who hid snacks in his desk, thinking no one noticed.]
[You said you wanted to visit quieter places. That it had been so long since you went outside.]
[It's fine. We have plenty of time now, don't we?]
[Satou and the other superiors are gone. They won't suddenly appear to monitor us.]
[So, what do you think?]
[Mr. Takakai, oh, and your student, little Shinomiya. But you really shouldn't bring dogs to school.]
[Shall we go for a walk? Staying in this classroom is so dull, isn't it?]
[Ah, you agree? Wonderful. Let's go.]
[I've always wanted to talk about the past—how long we wasted here, how it all amounted to nothing.]
Thud. Thud.
[Why the strange expression, Mr. Takakai? We're friends, aren't we? Footsteps? Probably just someone passing by. Nothing to worry about.]
[You're asking about a child's name?]
[What child? I'm not sure… Huh? The child Satou locked away?]
[What a strange question…]
Thud. Thud.
[You insist I must know? Because I'm your friend?]
[You're being very odd… I…]
[Fine, fine. Figuring out that child's issue wasn't easy, but of course we succeeded. How could a child hide from us? Remember when we investigated together? We… Huh? You just want the name? Mr. Takakai, you're so impatient. Is that any way to talk to a friend?]
Thud. Thud. Click.
[Ah, someone's knocking. So—Wait, Mr. Takakai, why are you so fixated on that name?!]
[Alright, alright, stop—I know it, I know the name—Why are you—Fine, fine, calm down!]
[That girl's name is Hachiya—]
CRACK.
Thud—