On my way back to the East Wing, I heard voices coming from the courtyard. It seemed that Akizuki-san and the others had come out of the changing room.
“It’s like a ghost story, isn’t it? The door suddenly not opening… I hope it’s just a problem with the fittings.”
“Hmm, I don’t think it’s bad enough to call a contractor.”
“Erisa, if you’re scared, we can sleep together like we talked about earlier?”
“Since Haruka went over to Nanami-san’s side, it doesn’t seem like the second-years are staying together, and staying with Akoya doesn’t feel any different from usual.”
“Then how about tonight your big sister stays with you? Oh, by the way, what happened to the person we brought back from the dungeon? She was supposed to stay in Shiro-chan’s room, right?”
“Wait, there’s someone like that? You mean you brought someone back from the dungeon… were they a lost person?”
“The underclassman keeps accomplishing something in the dungeon every time… I should try to learn from him, but the stars tell me to live a low-profile life.”
“There’s no way you could be low-profile… You’re wearing the boys’ uniform, and it looks good on you, but when you wear girls’ clothes, you’re annoyingly cute.”
I was only grateful that Akizuki-san accepted the dungeon’s manifestation without any fuss. If we couldn’t stay in the dorm, I would have had to set up a tent outside.
“Ah… Tsukasa-kun, were you waiting for the bath?”
“No, actually, about the person Akizuki-san was just talking about—the one we brought back from the dungeon. It seems she left her room, and I’m about to go look for her.”
“I see… I hope she didn’t go outside. If she’s not in the West Wing or the Main Building, maybe she’s in the East Wing.”
“Maybe she’s trying to get into the forbidden room.”
“Who knows… but I doubt the door that hasn’t opened since we got here is going to open now.”
“I have no idea what she’s thinking… She’s not a bad person, though.”
Akizuki-san knows who’s in the forbidden room, but they’re not particularly close. This means the room and its occupant existed even before she became the dorm manager.
“Well, let me know if anything comes up, and I’ll help you out. I’ll add one favor to the list.”
“You could just say you want me to rely on you.”
“Well, you handle most things on your own, Fujiwara, so there’s no cuteness in asking for help.”
“You’re much closer now than you were at the beginning though, aren’t you? Hehe.”
“Stop it, don’t tickle my sides—I’m weak there! I’ll report you for dorm manager misconduct.”
“Erisa’s weak to tickling, so remember that, underclassman.”
“Ha… I wouldn’t want to upset Kashino-senpai by joining in.”
“Everyone’s weak to tickling! Fujiwara, let’s have a tickling match next time—I won’t stop until that calm face of yours breaks.”
“…Only if there’s someone else with us.”
Akizuki-san offered her advice, but Kashino-senpai puffed up her shoulders and left. The three of them headed into the living room, though they would probably go to their rooms in the West Wing soon enough. Since Rin’s illusion had worn off, there wouldn’t be any problem if they got near the West Wing.
I entered the East Wing through the side entrance—now that the illusion had faded, I shouldn’t need to be as cautious anymore. At least, I thought so.
(…What’s this?)
At the far end of the hallway was the forbidden room. Something seemed to be glowing in front of it.
As I got closer, I saw letters floating on the surface of the door.
“Enter quietly, alone.”
I should be looking for the dungeon manifestation, but—if this message is meant for me, should I respond?
As I pondered, the letters changed. There was no mistake—the person inside the room was communicating with me through these words.
“Enter, or I will curse you.”
It felt like a scene from a horror movie. For safety’s sake, I should probably consult Akizuki-san, but the last time I spoke with the room’s occupant through the door, they didn’t seem like a bad person.
When I touched the doorknob, it turned more easily than I had expected.
Upon opening the door and stepping inside, I saw a room slightly larger than mine, filled with bookshelves.
There, next to a person wearing a black robe and a hood, was the embodiment of the dungeon—a girl with faint features, almost ethereal.
“…That girl, I brought her to this dorm. Did you invite her into this room?”
“Quite polite, aren’t you? Not mad about bringing the dungeon core here without permission?”
The figure was visibly small and had a youthful voice, but their words were sharp, making it clear they weren’t as young as they seemed.
And that word—’dungeon core.’ Rin had called her that, and now this person did too.
“I never thought I’d meet a person who’d bring a dungeon core to a dorm. Let me clarify something: I had nothing to do with the illusion created by Lilim. It was just a coincidence.”
“Rilim… Is that Rin’s species name? You seem to know a lot of things I don’t… Impressive.”
“…Well, you have a disarming way about you. I’ll just say it—I am, in essence, a dungeon researcher. I’ve only met that child—Sumi—once, but you could say we’re acquaintances.”
“A dungeon researcher… Are all these books related to your research?”
“Not exactly. Many of the books found in dungeons have nothing to do with dungeons themselves. Sometimes, we don’t even know the language they’re written in, and it’s common to not find the resources needed to decipher them. It’s like wandering in the dark without a light.”
“…The fact that books can be found in dungeons surprises me.”
It’s hard to imagine monsters creating books. Producing paper and inscribing it with text requires a species capable of using language. Only humans, or something similar, could make books.
“The beings deep within dungeons, the dungeon cores themselves, sometimes possess high intelligence. If so, it stands to reason that books could exist in dungeons. They could either create them with magic or steal them from explorers.”
“…In my dungeon, there were no books. And not all dungeons have entities like me.”
The embodiment of the dungeon spoke. Her voice was clear and somewhat fleeting, much like the voice that had echoed in my mind.
“…You were in Dungeon No. 2, but not all dungeons are the same, huh?”
“I believe most dungeons have cores. What’s rare is when the core creates a humanoid interface to interact with others.”
“An interface… meaning a form for communicating with people, right?”
“…Even I cannot explain why I took this form.”
“I thought so. Dungeons are meant to repel intruders. It’s exceedingly rare for them to seek communication… Do you understand, boy? You now hold the key to shaking the world.”
“…”
Even if I didn’t yet know why this dungeon core had appeared, I believed that I’d understand eventually.
I realized I had been walking a tightrope. If it had been anyone other than Mr. Iga outside the dungeon, if Akizuki had become suspicious of the ‘person brought back from the dungeon,’ things could have gone very wrong.
If that information were to spread, what would happen? The objectives of explorers could shift to ‘finding dungeon cores’ or ‘obtaining humanoid interfaces.’
“…How did you know she, the ‘dungeon core,’ came to the dorm?”
“Because I’ve been to the deepest part of a dungeon and have seen the core. The energy waves that spread throughout the dungeon can be traced back to the core.”
“So, you were an explorer… a highly skilled one, I assume?”
“That’s correct. You’ve probably guessed, but despite my youthful appearance, I’m much older than I look. It wouldn’t be strange for me to be as old as your mother, Tsukasa Fujiwara.”
Anything can happen in a dungeon. Even though I understood that, the situation of this person in the locked room was so unusual that my curiosity about why it had happened only grew.
“…Well, anyway. What I’m suggesting is that you can hide her here.”
“That’s a relief. But I don’t want to keep her locked away…”
“Indeed. Once the preparations are complete, she may be able to go outside. In some cases, she could even enroll in school as a student. But there’s no need to rush.”
“…Tsukasa Fujiwara. I don’t feel that it was a mistake for you to bring me here. In fact, I believe it was the right thing to do.”
“I hope so… Anyway, I’m just glad you’ve woken up.”
“I’m sorry for the trouble. She’s still in a pure state and is highly susceptible to illusions. If I hadn’t protected her when she came to the East Wing, there’s no telling what might’ve happened. Please understand that.”
Had she not been protected, what might have happened? The dungeon core girl didn’t seem to understand what I was worried about; she simply gazed at me without changing her expression.
“It might be better to give her a temporary name, as just calling her ‘the core girl’ could be confusing.”
“That’s true… or rather, does she already have a name?”
“………”
It seemed she didn’t have one, which meant naming her was necessary. Since “Dungeon No. 2” was a designation given by the academy, there was no need to derive her name from that.
“Well, it’s not something we have to decide right away, so we can leave it for later. Now then…”
“W-Wait, before you go, your name…!”
Before I could finish, she left without answering. The core girl, now dressed in borrowed clothes, was wearing a fluffy pastel-colored shirt and shorts. Despite her otherworldly aura, it seemed like any kind of clothing would suit her to some extent.
“I’ll show you around now, but you’ll be staying in Nanami-san’s room in the West Wing tonight. Does that sound okay?”
“What constitutes ‘okay’?”
“Uh, I guess it means there’s no problem?”
“I don’t need to sleep, but sleep is beneficial for this body. It reduces the consumption of magical power.”
So, she functions almost like a human—restoring physical and magical energy through sleep. From what I could tell, there didn’t seem to be any major differences between her and a human.
However, I couldn’t help but notice her shirt, which was lifted by her chest, creating a noticeable bulge. The shirt was a bit short, pulling upward and exposing her stomach. I couldn’t bring myself to say anything about it at that moment.
“This garment has high thermal insulation, causing my body temperature to rise slightly. May I remove it?”
“W-Wait a minute…!”
Without waiting for an answer, she began to take it off—her movements causing certain things to almost burst free. I quickly closed my eyes and managed to stop her in time.
“Y-You should only take your clothes off in private, or when you’re around people of the same gender. It’s really important to follow that…!”
“Why is that?”
She asked, sounding genuinely displeased. It seemed there was no room for debate—hiding her in the dorm was clearly the right decision.
