Facing the master of the 2nd floor—Inoue Hiiro, Inoue san gulped audibly.

Fragments of beasts tightly plastered across the entire wall.

The smell of blood and wildlife filling the room.

Embedded in the center of that giant chimera, Hiiro san hung her head in agony.

"Hiiro!"

Inoue san cried out and ran over to Hiiro san.

Startled by the voice, she raised her head, widened her eyes at the sight of her supposedly dead sister standing there, and muttered, "No way..."

"It's been a while, Hiiro. I've been looking for you all this time."

"Big sister, no, don't come closer!"

"Eh—?"

The beasts on the wall, which had vacant eyes, all turned their gazes toward Inoue san at once.

Then, opening their mouths lined with sharp fangs wide, they extended their spines and lunged to bite her.

Inoue san readied her tonfas and smashed the head of the wolf leading the charge.

When she did, Hiiro san let out a pained groan, "A, guh...!"

"The pain is linked too!?"

Realizing this, Inoue san was clearly shaken, and her movements dulled.

I immediately kicked off the floor and closed the distance to her, grabbing her body and pulling her away from Hiiro san.

I hear a series of sharp, clanging sounds directly behind me as the bite misses its target.

"Th-Thank you, Erika chan."

"Hiiro san, why... it shouldn't have attacked us yesterday."

"Could it be because you saved Ai...?"

Ushizawa san said apologetically.

At that, Hiiro san shook her head from side to side.

"It's not Ai's fault. I'm just... pathetic. If I get even a little hungry, I lose control immediately."

"So as long as your hunger is satisfied, you can control it."

"That's why you made them bring massive amounts of food as tributes every day."

In short, Hiiro san had been deceiving Ooki and the others about that aspect as well.

"Why... did you end up with a body like that, Hiiro?"

"More importantly, Big sister! Why are you here—"

Hiiro san stopped mid-sentence.

Then, as if realizing something, a sad expression washed over her face.

"A Cast..."

"...I see. So you are also a type of Cast, Inoue san."

"What do you mean? I'm a Cast? I don't have a name tag."

"But you have that pendant with the clover."

When I said that, Inoue san pulled the pendant from her chest and tilted her head. "This?"

"I think that served as proof that you are 'Inoue Hiiro's older sister' even more than a name tag would."

"Ai knows that. It's the pendant Hiiro kept as a memento of her older sister."

"But when I came to, I was holding this."

"That's... because I dropped it while I was running around the amusement park trying to escape."

A human who gets their hands on a name tag is forcibly transformed into a Cast even if they haven't zombified.

In other words, it was entirely possible that the person who picked up the dropped pendant turned into Inoue Yoshino.

"Hiiro san. Could you tell us what happened that day?"

She nodded obediently and began to recount the events that had happened to her a few days ago.

"It started when I found the director of this amusement park injured."

◇◇◇

Upon seeing the injured Tsumori san, Hiiro san immediately rushed over to him.

According to her, seeing his injury instantly reminded her of the incident with Yoshino san.

The gunshot wound left on his abdomen.

And the fact that the person killed was someone close who had been investigating Kaisei kyou.

To treat Tsumori san, Hiiro san lent him her shoulder and they entered the office.

However, the wound was deep and not something that could be fixed with the tools in a first-aid kit.

Gradually weakening and with his consciousness fading, Tsumori san told her what had happened to him.

『It's that woman... the culprit, who killed Yoshino san...』

『Who is it!?』

『A teacher at Hikarinomiya Academy... Ooki Ranko...』

The reason Tsumori san knew Okoi's name was apparently because she had come up as one of the suspects in Yoshino san's murder.

After the school building and the amusement park merged, the two had coincidentally encountered each other.

And when Ooki approached Tsumori san, she said:

『Tsumori—the man who was sniffing around Kaisei kyou. You are not fit for the True World.』

Saying that, she fired.

It is highly likely she used a gun that had been hidden in the school building.

The culprit from six years ago was also Ooki Ranko.

Perhaps Ooki managed to climb to the position of an executive through the "achievement" of killing Inoue Yoshino.

Hearing that, Hiiro san was shocked.

To think her beloved sister's murderer was so close.

To such a Hiiro san, Tsumori san continued to smile until his very last moment.

And to grant Hiiro san's dream of wanting to become the director—he entrusted her with his name tag.

After watching over his death, Hiiro san left the office.

But at that moment, an anomaly occurred in her body.

Her body suddenly expanded, and parts of Hikarinomiya Fantasy Land's mascots began emerging from inside her.

They multiplied and expanded one after another, and in the blink of an eye, Hiiro san transformed into a monster.

The mascots, which were initially just cloth dolls, eventually became real beasts, indiscriminately attacking the people around them.

Having lost so many things all at once, and filled with despair at having turned into a monster herself, Hiiro san went mad.

It was then.

Before her, having become a monster, Ooki appeared.

Looking at the giant monster committing endless slaughter, Ooki wore an ecstatic expression and said:

『Are you Giraiguu sama?』

Believing the descent of Giraiguu was a success, Ooki likely assumed the main body had to be somewhere on this floor and was searching for it.

And she mistakenly believed Hiiro san, who had become the master of the floor, was Giraiguu.

She decided to play along with it.

As the sister of the victim and someone connected to Tsumori san, Hiiro san knew quite a bit about Kaisei kyou.

『Indeed, I am Giraiguu. Well done making the ritual a success; I shall praise you.』

『I am unworthy of such gracious words!』

Ooki prostrated herself before Hiiro san.

Completely unaware of the murderous intent held in the eyes looking down at her.

Thus, Hiiro san headed to Oki's base, the hotel.

Then, a change occurred in the building.

As if welcoming the master of the floor, a Throne Room was born in a place that was merely a warehouse.

This mechanism was likely similar to the space Shimakawa Yuya had created.

Hiiro san began spending her time in the Throne Room, demanding massive amounts of food to soothe the beasts that made up her body and maintain her sanity.

◇◇◇

"And my plan was to just wait for destruction."

"Hiiro... you intended to die along with this space."

"Ooki sensei and the others firmly believe there is a True World beyond the destruction. I thought that if I used that against them, I could kill them."

"Ai doesn't understand. Hiiro should have power. You could have just killed Ooki sensei."

Hiiro san shook her head to deny it.

"If my stomach isn't full, my reason is dominated by Kaigyo. When that happens, these beasts won't attack Ooki sensei and the others who are 'allies'. It's the same as the Casts and Hole-Men. I had to do something using my own will."

That was exactly why Hiiro san waited.

She waited, hoping for the world to rot away completely, for destruction to come naturally.

"But... to think Ai and the others would come. And even Big sister! I don't... know what to do anymore..."

As if linking with Hiiro san's confusion, the beasts also wriggled.

As expected, even she hadn't planned on getting her best friend Ushizawa san involved just to kill Ooki.

"Hey, Hiiro. I'm just happy enough that I could see you grown up like this."

"Big sister...?"

"If I am just a Cast holding a human form because of this pendant, wouldn't I disappear if the 'master' is killed?"

"Eh... N-No. I don't want that!"

"Ai doesn't want that either. No matter what form it took, if Big sister came back to life, Ai wants her to stay alive!"

"It can't be helped. I am sustaining a life that shouldn't exist by sacrificing someone else's life. So, don't worry about my life. Also, if a problem arises that can't be solved without sacrificing someone, I want you to prioritize cutting me off. This is a request for Erika chan too."

"Big sister, why would you say such a thing..."

"We understand your resolve, Inoue san, but we haven't found any solutions yet anyway. In short, Hiiro san just doesn't want to drag her family and friends into this, right?"

Hiiro san nodded her head vigorously up and down.

"We can think about how to defeat the master later. For now, let's think about how to save Hiiro san."

"Can I be saved?"

"Do you yourself know that the core of the Casts is the 'name tag', Hiiro san?"

"Yes, because that was decided by my subconscious. I did a truly terrible thing... to the staff members."

Since she became the master, she grasps those mechanics too.

Yet she still can't completely control Ooki and the others, which means the flow of power must be on a different line from the Casts.

"Kaigyo is the one doing the bad things, so don't worry. you also have Tsumori san's name tag, right?"

"Yes, it's... nngh."

As she let out a voice as if putting strength into something, a rabbit's face smoothly extended towards me.

In its mouth, it held Tsumori san's bloodstained name tag.

"Erika chan, if we throw this name tag away, will Hiiro be saved?"

"I wish it were that easy. You can't let it go, right?"

"Yeah... even if I try to let go, it won't detach."

I stared intently at the name tag to observe it, but honestly, I didn't feel like I could destroy it.

If even the Casts' name tags were that hard, the master's might be dozens, perhaps hundreds of times sturdier.

On the other hand, I didn't think just cutting it off would solve anything either.

As a test, when I pointed Dreamer at it, the name tag quickly retracted.

"That definitely wasn't my will just now!"

"I know. Kaigyo probably has no intention of dying either."

When I sheathed the blade, the name tag popped out of the rabbit's mouth again.

In the first place, why did a situation where "the name tag becomes the main body" occur on this floor?

I think Tsumori san was originally intended to be the master of the floor.

He must have harbored considerable resentment toward Kaisei kyou and Ooki, so it wouldn't be strange for him to be selected as an avenger.

However, he was killed by Ooki before his power could awaken.

To put it plainly, it was like when I killed Shudou kun.

But unlike Shudou kun, they couldn't leave a major role like the floor master vacant.

Yet, unable to drastically change the target from Tsumori san, with whom the pipe was already connected—seeing him transfer the name tag to Hiiro san, it decided to pour power into the name tag instead.

As a result, the Casts generated in tandem also ended up using name tags as their cores.

However, even after obtaining all this information, I still ultimately didn't understand why Hikarinomiya Fantasy Land was dragged into this.

Tsumori san, Ooki who killed him, and Hiiro san who ended up becoming the master; all these events happened after Fantasy Land and the school building merged, meaning there is no connection between these events and the merger itself.

In that case, it really must be—Yumemi chan.

I don't know what state she's in right now.

Since Nemusia is here, she probably doesn't have a physical body, but traces of something resembling Yumemi chan's will can be felt in every corner of this world.

The reason Hikarinomiya Fantasy Land was chosen was also because it's a place full of memories for me and Yumemi chan.

I bought the keychain attached to this Dreamer at this very place too.

And it's also where we decided to elope together.

Yumemi chan hesitated for a moment, but gave me her answer right away.

She told me she would throw away anything if it was for me, and she truly meant it.

And yet, and yet, I convinced myself she had betrayed me—

...This is bad, my thoughts are going in a weird direction.

Yumemi chan is important, but right now I have to focus on Hiiro san.

"I wonder how we can peel the name tag off Hiiro san..."

Rea put her hand to her chin, lost in thought.

While the others were also lost in thought, an idea popped into my head.

And I reached out toward the name tag.

Since I didn't draw my weapon, the rabbit didn't swallow the name tag.

"To Ai, it looks like Kuragane san is about to do something dangerous."

"Even if severing it is impossible, I thought 'transferring' it might be."

"It was already transferred from Tsumori san to Hiiro, after all."

"I don't know what will happen to me either..."

"It's worth a try. I'll try grabbing it for just a second, so if I start acting strange, pull me away immediately."

Rea nodded anxiously.

When dealing with the Casts, the name tag didn't react at all even when I touched it.

Since we possess the power to purify Kaigyo's energy with a filter, it might be set up to reject things like us.

Besides—there was also something I wanted to confirm.

I touched Tsumori san's name tag with my fingertip, truly just lightly.

In an instant, something dark and muddy flowed into me like a raging torrent.

『Did you kill her? Did you kill herrrrr!』

『Die! Everyone just diiiie! This is retribution for stealing my familyyyy!』

『Ohohoho, rotting. Everything is rotting. A fitting end for this world!』

『A world like this should never have been born in the first place! This world that takes everything precious from me! So please, don't stop me, Nemusia! You're someone on the 'robbed side' too, aren't you!』

『Calling me here. Teaching me the taste. This treatment... is unforgivable. I will not forgive all of humanity!』

『It hurts. It hurts. It's agonizing. It's agonizing. Help me. I want to see you. Erika—』

This is—the mass of hatred Kaigyo has devoured?

This is bad, it's coming in, it's coming in, the "Gangrene" is filling my body!

The filter was broken through.

Beyond that lies your,

my absolute favorite food.

"Gi, ah, gah, aaaaaaaaaaah! Agah, hih, higih, gugaaaaaah!"

"Erika, are you okay!? Erikaaa!"

Let's break through the fangs and pop the membrane.

I'll slurp the black honey inside.

Sweet.

So sweet.

It tastes like sludge.

I love it so much.

I'll eat a looooot, a loooooot, and grow big—shut up, shut up, you're Kaigyo, aren't you.

I'll eat.

I'll eat a lot.

I'll swim freely in this vast ocean, eating whatever I want—so I'm telling you, it's so annoying, that innocence of yours!

"Gugeeeoeh! Gah, go, C-Cure...!"

I cast Cure on myself.

Then, the inside of my body was purified all at once, and the Gangrene vanished somewhere.

Rea, clinging to me, hugged me tightly.

"Haa... haa... haa..."

"Geez, you're too reckless... your face looked like a zombie!"

"S-Sorry."

"If you get like that, even you wouldn't be cute anymore, Erika, you know!?"

"That's... something I don't want."

I don't think of myself as cute, but I guess I wouldn't want Rea to stop thinking so.

"But, with this we know that 'transferring' is possible. Right... Hiiro san."

"Just now, a tiny bit of Kaigyo's power drained from me—so I think so."

"Then Hiiro can return to being human!"

"Thank goodness... Ai can be with Hiiro again."

If transferring is possible, the plan I have in mind should work.

Besides, I figured out the mechanism of the world.

Kaigyo's desires.

The voices of hatred.

The logic of baring fangs.

Yumemi chan's lingering scent.

I had a feeling it might be the case, but—it really is.

So that's how it was, this world.

There are many things I could only understand precisely because I connected directly with the master who is tied to Kaigyo.

"But, even if I survive, Big sister will..."

"Hiiro. Like I said before, I'm a person who shouldn't exist. If you turn back to human, I think I can hold you tight until this master thing dies. Could you forgive me with that?"

"No... I wanted to see you so much. Ai and I went to your grave so many times. We kept saying we wanted to be spoiled by you again like back then!"

"I see. You too, Ai chan?"

"Of course. Ai was raised being spoiled by Big sister."

"I certainly have known you since you were little but... ahaha, this is troubling. Of course, if it were possible, I'd want to do that too."

Then what should I wish for?

I thought achieving revenge would be enough.

If I could survive and escape outside after that.

I thought that alone would be enough.

But, if this is a prepared stage.

Maybe what I should seek is actually something different.

"Then you should do that, Inoue san."

"Eh? But doing that—"

"If I say it's possible, will you still refuse?"

"...That's."

She won't refuse.

No—she can't refuse.

Anyone with lingering attachments to this world would feel the same.

"Erika, did you think of something?"

Rea said while looking at my face.

Maybe I was making Nemusia's "older brother face" again.

"If I said there's a way for everything to go well, would everyone get on board?"

Knowing no one would refuse, I made the proposal.

At the same time, it was also a method to make Ooki suffer and die in the worst possible way.