Somehow I Ended up Dating the Perfect Female Classmate, but My Sister Found Out and They're Turning Into Yanderes - Chapter 42-43

Chapter 42: Scary Photo

“It’s hot, too hot…”

In the scorching midsummer heat, Ayuka and I were pedaling our bicycles.

Even in this sweltering weather, I didn’t see much sweat on Ayuka’s forehead.

…Ayuka’s sweat, I thought it could be used as material.

“Phew, we finally made it.”

The moment we reached the tutoring school’s bike parking area and stopped, I put my hands on my knees.

I felt like I was going to throw up.

“What, you’re already giving up just from this? Didn’t you run to the sports gym with that girl before?”

As usual, Ayuka didn’t offer me words of encouragement but threw sarcasm instead.

“Are you still holding a grudge about that?”

“Huh? Why would I hold a grudge about you going out with that girl?”

Here comes the tsundere.

Sure, I said a tsundere little sister is in demand, but Rinka’s already enough.

“Come on, let’s go. We’re running out of time.”

The summer classes at this tutoring school usually start around noon.

I had a cup ramen from the convenience store for lunch today.

Now, it felt like that cup ramen was about to come back up.

“Well, see you later, big brother.”

Ayuka walked off to the classroom for high school entrance exam students.

Come to think of it, does she have any friends?

I heard rumors that attending a group tutoring school makes it easy to make one or two friends.

I thought I was the exception, but I’ve never seen Ayuka talking with anyone at the tutoring school.

No, even before that, does she have friends at school?

Since Rinka stopped making dinner for Ayuka, she said she’s been eating out with friends, but I couldn’t help but feel suspicious.

“Should I follow her next time during dinner?”

Of course, Rinka wouldn’t let me skip dinner, so there’s a risk involved.

Well, there’s no point thinking about that now.

I need to hurry to the classroom.

Being late and walking into class at the tutoring school is way more embarrassing than at school.

“…”

When I silently opened the door, most of the students were already seated, but luckily, the teacher hadn’t arrived yet.

“Huh? Kirino isn’t here…”

Well, that makes sense.

A lot of middle and high school students attend this tutoring school.

So, it’s only natural that the chances of being in the same class as Kirino aren’t that high.

“Alright, let’s start the lesson!”

As the teacher walked in, I took my seat.

“Phew, the lessons are surprisingly long.”

After class ended, I was at the vending machine on the first floor of the building, buying and drinking a Calpis.

The tutoring lessons last about an hour, a bit shorter than school classes.

Still, for someone like me who can’t absorb the material, it feels long.

“Oh, there you are, Kiyoto-kun.”

At that moment, I heard a beautiful voice from the stairs.

“K-Kirino-san?”

Kirino-san was standing on the stairs, looking down at me.

With that super heavy expression.

“I was waiting for you until just before class started, but I didn’t see you. I thought you were trying to avoid me.”

“N-No way, me avoiding you? That’s impossible!”

What does she mean by avoiding!?

Why would she say something like that?

“Yeah, you’re right. Since you’re here, it proves you weren’t avoiding me.”

Kirino-san came down the stairs, her footsteps making a clacking sound.

She walked slowly and heavily with that expression.

…Honestly, it’s super scary.

I understood how people in horror shows feel when they encounter a ghost and get paralyzed.

“Uh, um, is something up, Kirino-san?”

“Hm? Something?”

“Well, it’s just… you seem more mature today or something.”

I couldn’t help but phrase it positively.

I couldn’t say her vibe was scary.

“Hmm, so that’s how you see it, Kiyoto-kun.”

Finally, Kirino-san reached the bottom of the stairs and stood in front of me.

“I agree my vibe is different, but I wouldn’t say it’s because I’m more mature.”

As she said that, Kirino-san took out her phone from her pocket and showed me the screen.

“I think the reason my vibe is different is because of this.”

“Ah.”

When I saw the screen on Kirino-san’s phone, the word “ah” slipped from the bottom of my heart.

What was shown there was

“This is you and Rinka-chan, right?”

It was a picture of me and Rinka chatting face-to-face at a family restaurant.

—

Chapter 43: Invitation to a Battlefield

“This is you and Rinka-chan, right?”

Kirino-san stared at me with those deep, dark eyes.

Now, how should I explain this?

No, wait, what’s wrong with this photo in the first place?

It’s just a picture of a brother and sister at a family restaurant.

Just a snapshot of daily life.

Kirino-san knows Rinka is my sister.

So, there shouldn’t be any problem, right?

“…”

But if that argument worked on Kirino-san, who’s in full yandere template mode right now, I wouldn’t have to rack my brain like this.

I know.

If I made that argument, it’d lead to a stun gun and confinement ending.

I’ve studied enough yandere situation scripts to know that.

“W-Well, this is just a photo from when we went out together.”

“Hmm. A date for the two of you? That sounds fun.”

This is bad, really bad.

Her voice is getting flat and emotionless.

“N-No, I mean, it’s a date, but we’re just brother and sister, so it’s a different kind of date.”

“A different kind of date? What exactly does that mean?”

When she asked that, I couldn’t find the words.

“And this is that Rinka-chan? The Rinka-chan who’s your sister but doesn’t have a shred of cuteness? That Rinka-chan is making such a feminine face?”

If you say that, I’d start doubting if it’s really you, Kirino-san, spitting venom at Rinka unconsciously (or maybe consciously).

Also, what’s with this “feminine face” thing?

Sure, Rinka in the photo does seem to be smiling a little.

Is this from that time?

When I told Rinka I’d go cheer for her at the Kanto tournament?

Just a slight smile like this counts as a feminine face to Kirino-san?

“W-Well, I think Rinka was happy because we got to exercise together after a long time.”

“Exercise?”

Oh no.

I shouldn’t have said that.

“Actually, that day we went to the Joto Comprehensive Sports Center together.”

“A date at a sports center? That’s so like Rinka-chan (lol).”

That (lol) was definitely a mocking laugh.

“So, to sum it up, you and Rinka-chan went to the Joto Comprehensive Sports Center that day, and then went to a family restaurant that night???”

“Y-Yeah, that’s right.”

Everything depends on Kirino-san’s reaction from here.

“…”

Kirino-san suddenly went quiet, lost in thought.

Her eyes were still on me, but I didn’t feel like she was “looking” at me, so I could tell she was desperately thinking about something in her head.

“…You’re right. Since you and Rinka-chan are brother and sister, it’s natural for you to go out or eat together.”

At least she understands that much.

“But lately, Rinka-chan is totally trying to go beyond the brother-sister concept. Well, it’s cute how you innocently agree to a date without realizing it.”

I got called cute…//

“But I can’t just let it slide. Oh, I know! Hey, let me stay over at your house sometime this summer.”

“Huh?”

“I was thinking of having you stay at my place, but first, I need to show your sisters that you and I are properly in a romantic relationship.”

“K-Kirino-san, you’re coming to stay at my house!?”

“Yeah, that’s right.”

All I can imagine is a complete battlefield…

But there’s no stopping Kirino-san now.

Also, her talk of “showing off” is kind of tickling my masochistic side//

“Hey, what are you doing there?”

While I was imagining Kirino-san staying over at the Nuregami house, another voice came from above.

“…Here comes another one of your sisters who’s not as cute as Rinka-chan.”

“Huh? Don’t lump me in with that girl.”

Oh, this is going to take up more time.

“But sorry, class is about to start, so I don’t have time to deal with you. Come on, Kiyoto-kun.”

Kirino-san grabbed my hand tightly and started climbing the stairs.

…Is it a common thing that their strength increases when they go into yandere mode?