Marin irritably pushes back the rose Hiyami san held out to her.

Then, she points the tip of her sword at me once again.

 "We had an interruption, but that doesn't change the fact that I'm going to kill you."

"Didn't I tell you to stop?"

"We don't have the kind of relationship where we stop just because someone says so, that's what sisters are like."

It's probably quite far removed from general common sense, but when it comes to Marin and me, that's correct.

"I've never heard of sisters like that, you're quite twisted, aren't you."

"It can't be helped. Marin was raised being told that I'm a worthless person, a disgrace to the Kuragane family."

"Do you think that's the only reason?"

"Even if it's not the only one, it's an undeniable fact that it's at the root of it."

"Calm down, both of you. Knowing Marin's strong sense of justice, it's not incomprehensible to be angered by acts that desecrate the dignity of the dead, but I think you're letting personal feelings get involved a bit too much."

"Ruka, you saw it too, that corpse left hanging! A boy named Asanuma from Class 2-B—in the same class as Erika. A person who can commit such an act should no longer be called human!"

Ah... Marin found that, huh.

And from the sound of it, it seems she gave him a burial.

And I went to the trouble of hanging Asanuma kun so nicely!

"Marin really always gets in my way."

"Look at those beast-like eyes full of murderous intent. I knew she did it! The woman named Kuragane Erika is a sub-human failure lacking both intelligence and reason! Giving her power is out of the question. That man turned into a living corpse is the result!"

"Maybe so. Since Marin sucked all the cunning and everything else from our parents."

"That filthiness is something you were born with!"

"What are you saying? Using Asanuma kun as an excuse to want to kill me makes you the lowest of the low, I almost want to learn from you."

"To toy with the dead and then push the responsibility onto me!"

"Don't act all self-righteous after freeing someone who deserved to suffer, you cuckoo chick who stole everything from me."

"Erika, youuuuu!"

Marin slashes at me with bared murderous intent.

Provoking her, I bare my teeth in a smile and take a fighting stance.

However, Hiyami san stops Marin by putting her in a full nelson.

How boring.

"Don't stop me, Ruka! We must eliminate this woman for our own survival!"

"I don't dislike passionate Marin, but that's going a bit too far."

"But I cannot forgive being called a cuckoo!"

"Ahahaha, I don't know why, but you always snap when I call you that, Marin. You monopolize all our parents' love and money, don't you feel any guilt? I'm not even allowed to eat at the same dining table."

"As if a person who doesn't make an effort to be loved can say that!"

"Try saying that same line to the two-year-old me. I think she'd tilt her head looking like she has no idea what you're talking about."

"Shifting the blame like that!"

"Whoa, whoa, whoa, calm down, Marin."

"Why do you only stop me!"

"Because, no matter how you look at it, your family environment is abnormal, Marin."

Surprisingly, Hiyami san doesn't seem to be taking Marin's side.

No, maybe this is taking Marin's side.

To be clear, objectively speaking, there's absolutely nothing wrong with me regarding this matter.

"Ruka, are you taking Erika's side?"

"I'm talking common sense. I always thought it was strange since you never talked about your family before. But the truth was far more abnormal than I imagined. Sisters aren't even allowed to sit at the same dining table? What's going on with your family, Marin?"

"That's because... Erika is the cause..."

"Is there something? If there is, I'd like you to tell me."

"...Ugh."

"Take a deep breath and calm down, Marin. Being the intelligent Marin you are, you must be aware that your environment is abnormal, right?"

"That's... no, I know that... but..."

I've never seen Marin look this downcast.

It seems her self-proclaimed title of best friend isn't just for show.

"If you were raised that way, talking about it here won't solve anything. Children are influenced by their surrounding environment more than you imagine, after all. To solve it, you have no choice but to talk it over with your parents as well. So, clashing here with just the two sisters is fruitless."

"That's true... Ah, you're right. If dialogue was an option for us, we would have done it a long time ago."

"Rather than dialogue, how about show some kindness and listen to my voice?"

"Shifting the responsibility again—"

Am I really shifting the blame that much?

It's a fact that I'm not treated as family at home, and Marin has been told by our parents that I'm trash, so she's supposed to hate me like that.

Because, in reality, I've never truly "stolen" anything from Marin.

"Sigh, fine. Ruka, since you stopped me, I'll have you take responsibility and talk to Erika."

"I don't mind, I'm interested in your older sister, Marin."

I'd rather this person not be too interested in me.

"Erika senpai, was it? First, could you tell me what Marin is like at home? Like the color of her pajamas, or the brand of her toothbrush."

"Ruka!!"

"Oh, scary."

"Take this seriously."

"I am being completely serious, though..."

What am I being forced to watch?

"Hahaha, my apologies, Erika senpai. Because of love, I tend to go out of control when it comes to Marin."

It seems my exasperation showed on my face.

Naturally, since I had no intention of hiding it.

"First of all, I'd like to ask you something, Hiyami san."

"Whatever you wish."

"Did you and Marin also have your smartphones go weird and suddenly gain the power to fight, just like me?"

"I can't say if it was 'suddenly'. Marin and I worked together to repel a monster attacking people, and when Marin delivered the finishing blow, she suddenly heard game-like words saying 'Level Up'. At the same time, the bamboo sword she was holding changed its shape into a real Japanese sword."

"So it's the same as me."

"Hmph, I doubt you would kill a monster for someone else's sake, Erika. How did you get that power?"

"By killing an evil monster with these hands?"

When I answered that, Marin glared at me as if looking at her parents' enemy.

Haha, even though you're the one who stole so many things from me.

"So after Marin defeated a monster, Hiyami san also defeated one and became able to fight."

"That's not it. She put me in her 'party'."

"Party?"

Another game-like word came up.

Well, it's a bit late for that now.

"It should be on your smartphone too, Erika senpai. According to Marin, it appeared after she surpassed level 10."

"Hey Marin, should I look at the skill screen for that?"

"...You're being too familiar. It's not skills, if you swipe up or down from the status display, it should come up."

"Oh, you're right."

I thought I touched everything, but I really hadn't noticed this until now.

"It seems slaves registered in the party gain the same power as the master. Though, of course, Marin is the one who actually allocates the numbers. The master can constantly grasp the slave's location, and dissolving the party can be decided solely by Marin. In other words, if I displease her, it's over."

"If you disappeared just from displeasing me, you'd have been gone a long time ago. Besides, I told you it's Leader and Member, not Master and Slave."

"I like 'Slave' better because it feels like I'm bound to you."

"Shall I erase you right now?"

"Hahaha, won't you forgive me in exchange for this rose?"

The rose makes a reappearance.

And it is once again pushed aside.

Do these two always do this?

But still, a party, huh.

Even if the party leader has authority, giving power to the other person also means there's a possibility of being betrayed.

Then who can I trust the most?

When I thought that, the first face that came to mind was—Rea.

Saying she wants to be of use to me, she would gladly fight alongside me.

But, what if she betrays me like Yumemi chan did.

And, if she were to lose her life in battle—thinking about that, I can't decide if choosing her as a party member is a good idea.

"Though I doubt there's any comrade who would fight alongside you, Erika."

Marin said, provoking me.

I return a wonderful smile that even I realize is obnoxious.

"Ah, that might be true. I have no interest in you, Marin, neither at home nor at school, but you sure know a lot about me."

"I can imagine."

"Then try using that rich imagination of yours. Why I made Asanuma kun like that."

"Why must I simulate filling my brain with sludge."

"Are you running away?"

"Tch... Every single way you speak gets on my nerves."

"Unlike you, Marin, I didn't have a fulfilling school life, so I got really good at reading other people's negative emotions, or rather, the signs of them being in a bad mood. That's why I know, the face you made just now was the face of someone asked an 'inconvenient question'."

"Do you think you read my mind? Sigh... 'Because I was bullied', are you satisfied with this answer?"

"Haha, so you do know. And judging from that face, it feels like you knew the specific details too."

"Do you think that level of excuse justifies it? No matter what kind of pain you suffered, there is no justification for desecrating another's life!"

"There is."

"There is not!"

"It's nice that blessed people have the leeway to be kind to others."

"This is a problem with your rotten personality."

"If so, the ones who made me like this are our family, including you, Marin, and my classmates. I am a mirror. A seed grown on malice can only become a flower that scatters malice."

"Blaming others—"

"Alright, alright, stop! How many times do you plan to repeat this argument, you sisters! I can't let my guard down for a second."

Even Hiyami san stopped us with a louder voice.

It's true I bit back too hard just now, my bad, my bad.

"This time, allow me to ask you a question, Erika senpai. Where is your base? Are there survivors with you?"

"There are. 8 people in the infirmary."

Marin looks at me suspiciously, glaring.

She really can't believe I helped others.

"8 people! That's wonderful, wouldn't you agree, Marin?"

"I suppose..."

"We have our base in Class 1-E, with 6 surviving students."

"Wha-, you're telling Erika our location!?"

"Even you know that cooperation is necessary to survive and escape, right, Marin? Although it might be an inconvenient coincidence for you that the other party turned out to be your older sister."

It's an inconvenient coincidence (miracle) for me too, since I was almost killed right off the bat.

"But... to cooperate with Erika, no matter what..."

Marin clenches her fists so tightly that blood seems to surface.

It really shows how much she hates me.

"To think you two are on such bad terms that you can't even agree after talking this much. Why did it turn out this way, even though you live in the same house?"

"Even if we live in the same house, I'm basically not allowed to be in the same space as the family, so when was the last time we even spoke properly, Marin?"

"I don't remember."

"For you to not remember, that must be a really long time ago."

"You...!"

Ahaha, she's mad, she's mad.

It's always me who feels bad, so this is fun and I can't help but tease her.

Even though I know what I'm doing is at the level of an elementary schooler.

"It's been like this since I can remember, so it's not like there was a specific starting point. Since a long time ago, I was always the only one left behind when we ate out or went on trips, and only Marin was allowed to take extracurricular lessons. My birthday was never celebrated either. Every time an event happened in the house, I was made to realize that I was the only one who wasn't family."

Thanks to that, I got used to the pain, which might be one of the reasons I survived in that hellish class.

Hearing that, Hiyami san fell silent involuntarily.

Marin looked at her with a slightly uneasy expression.

"...Ruka."

She called Hiyami san's name with a weak voice, like a princess.

Ooh, what's this, did you not want her to know?

Are you worried she might abandon you after learning about your dirty side?

You have a cute side after all, huh. Well, you reap what you sow, and it's way too late for that now.

What does Hiyami san think, now that she knows this—

"Haha, hahaha, ahahahahahaha!"

Suddenly, she let out a magnificent, three-stage laugh.

That scared the crap out of me, it actually made me tremble.

Even Marin looked dumbfounded at this.

"Nice, that face of yours, Marin, it's such a precious expression I want to cut it out and frame it."

"...Huh?"

"Normally, Marin is a perfect woman. Wanting to break something like that when you see it is what they call 'love'. But you rarely show 'cracks' to others. I see, so what you needed was 'family'. If I had contacted Erika senpai sooner, I could have seen such an imperfect side of you! What a waste I've been making!"

With flushed cheeks, Hiyami san threw her arms wide open and shouted loudly.

Ah... this person is a weirdo beyond my imagination.

And she's invincible.

Cornering Marin is meaningless if I can't beat this.

"Don't worry, Marin, my love has deepened even more! There's no need to be anxious, even if you become a frail existence like a wet chihuahua in the rain, my love will never cease! No, rather, my love is accelerating! The distortion hidden beneath your perfect persona is adorable!"

"I-I see..."

With no allies to ask for help, Marin could only twitch her cheeks and do her best to avert her gaze.

Well, for better or worse, she ruined the murderous atmosphere, so all's well that ends well, I guess.

It's clear that neither of us would benefit if Marin and I hurt each other as we were.

In a battle between those with equal power, it's unlikely I'd see a comical and ugly death that would satisfy me.

If she doesn't weaken more, I can't make her suffer.

"Oops... haha, it seems I've gone out of control from excitement again, how unlike me. Erika senpai, if possible, I'd like to know the exact locations of each other's bases. Could you guide us to the infirmary?"

True, even if we say the infirmary and Class 1-E, the shape of the school building has changed, and they are far apart, so it's difficult to remember the exact location without actually walking there once.

It's a little worrying to take these two with me, but Hiyami san seems like a weirdo but not a bad person, and Marin isn't a lunatic who would kill indiscriminately just because they're my acquaintances.

"Alright. In exchange, make sure you take me to Class 1-E too."

"Of course. That's fine with you, right, Marin?"

"You're going to do it even if I say no."

Marin reluctantly agreed and started walking forward alone.

I haven't even told her where the infirmary is yet, though the direction is right.

However—there was one last thing I absolutely had to ask Marin.

"By the way, Marin, before I guide you, can I confirm one thing?"

"What."

"Do you know about Kaisei kyou?"

Marin stops in her tracks.

She didn't glare at me—for some reason, she looked back with weak eyes.

"Why ask that now."

"Because I was really curious. Over a year ago, you dropped a Kaisei kyou flyer, remember? Why did you have that?"

"That paper was not mine."

"Then did you get it from someone?"

"From mother."

"...Ah, I see."

"I was invited to attend a gathering. I refused, though."

Saying that, Marin started walking again.

Watching her receding back, Hiyami san asked me in a low voice.

"Kaisei kyou... It sounds like the name of a suspicious religion, but what exactly is it?"

"It's a cult group plotting the destruction of the world. Perhaps the school turning out like this might be their fault."

"That is a surprising information. And to think your mother is involved in it. By the way, it's a fact that Marin is not involved with that religion. Because there is no record of her attending any suspicious gatherings."

"Record... how much do you grasp of Marin's actions?"

"Almost everything."

"Whoa."

She really is a stalker.

"But if your mother is a believer, then perhaps your circumstances, Erika senpai, are also—"

"I think it's just harassment."

I cut off Hiyami san's fantasy.

"At least, as far as I can feel."

"Then why go that far."

There was definitely malice there.

Not faith.

No, even if there was faith, hatred also existed separately.

If only I hadn't been born—my own parents directed such emotions towards me.

Especially my mother, who always looked like she wanted to kill me.

Marin must have been influenced by that.

"Maybe she didn't like that I remained a dropout forever, even though an excellent child like Marin was born?"

She didn't want to believe that children with such differences could be born from the same blood.

That is not their child.

I often felt such cold emotions from my parents' gazes.

"That's not a convincing reason. It's too much to just be hatred."

Hiyami san, seemingly unconvinced, left my side and lined up next to Marin.

Keeping my distance from those two, I started walking as well.

Even if Kaisei kyou was involved in my life, it doesn't change what they did.

If I can kill them, I want to kill them.

Making them suffer for as long as possible.

It's not just my classmates I feel that way about—my family too.