Somehow I Ended up Dating the Perfect Female Classmate, but My Sister Found Out and They're Turning Into Yanderes - Chapter 62-63

Chapter 62: The Beloved Little Sister

“It all started when I got too harsh with my siblings.”

The real start was probably when she began using both kindness and punishment on me.

“Got harsh with your siblings? How exactly?”

“…I didn’t make dinner for Ayuka and treated her like a stranger.”

Rinka openly admitted to completely ignoring Ayuka, hiding nothing.

Everyone’s eyes, except Rinka’s, turned to Ayuka.

Honestly, I expected Ayuka to smirk smugly and insult Rinka, but she just looked uncomfortable and turned her face away.

“Judging by Ayuka’s expression, that seems true.”

Satsuna seemed satisfied with that alone.

I expected her face to turn terrifyingly cold, like in a typical story, but instead, she flashed that villainous smile again.

“Treating your own sister like a stranger. For someone as needlessly overprotective as you, that’s quite bold.”

Anyone looking at Satsuna would know she wasn’t praising her.

“…So cheeky.”

Satsuna’s smile vanished, replaced by a blank, condescending expression, like a villainous noblewoman.

Rinka’s forehead started sweating more.

“Tell me, Rinka. Since when did you get so bold?”

“…”

Rinka, clearly being looked down on, stayed silent, unable to do anything.

“You’ve always been mediocre, yet you worked pathetically as the weak leader of the group. Since when did my pitiful, cute little sister become so great as to throw that away?”

“…”

Rinka showed no reaction.

She didn’t react, but her clenched fists were visible.

“…As expected, you can only boss around those below you. But that’s what makes you so lovable.”

Satsuna smiled at Rinka.

This time, it wasn’t just villainous—it was a purely malicious smile, looking down on her completely.

“Well, fine. While I’m here, I’ll turn you back into my cute little sister.”

A taming declaration.

No, for Rinka, it’s not erotic—it’s more like discipline.

Wait, though, “discipline” still feels pretty erotic to me.

“Huh? Aren’t you leaving tomorrow morning, Nee-san?”

Ayuka spoke up suddenly.

It seems she thought Satsuna was only staying for one night.

“No. I’ll be staying until late August.”

“What!?”

This time, I let out a reaction.

“What’s that, Brother? Are you saying it’s a bother for me to stay that long?”

“N-No…”

Yes.

To be clear, it’s a huge bother!

I was planning to enjoy my last high school summer vacation…

Sure, I’m a loner, but I have a girlfriend, so I thought I’d have a vibrant summer…

But with Satsuna here, it’ll be a thrilling summer in its own way.

“By the way, Rinka, were you harsh with Brother too?”

Satsuna asked, keeping her malicious smile.

If Rinka says she was harsh, Satsuna will probably mock me to death.

“No, I gave Kiyoto lots of kindness.”

“…What’s that?”

Saying “kindness” like that won’t make sense to most people.

But since Satsuna isn’t normal, it probably makes perfect sense to her.

Also, her expression switched fast.

She was all smiles a moment ago, and now she’s blank-faced.

“What do you mean by giving him kindness?”

“Exactly what I said. I gave Kiyoto my love, called kindness, and let him taste it. Sometimes, I even fed it to him mouth-to-mouth.”

Where’s the submissive Rinka from earlier?

And is she saying this misleading stuff to provoke Satsuna?

“…Come to think of it, I’ve become quite lonely.”

What’s this sudden confession?

“While I was at the dorm, I missed you all so much, sometimes even crying.”

Yeah, right.

No one’s buying that girly nonsense.

“So, I’d like someone to sleep with me in my room tonight.”

…Huh?

That’s a huge leap in the conversation.

And this pattern…

“So… you’ll do it, right, Brother?”

…I knew it would come to this.

“Sister, that’s a bit…”

“Satsuna-nee, a high school brother and sister sleeping in the same bed is…”

“Do you think you can tell me what to do?”

““…””

With Satsuna in full queen mode, neither could argue back.

I thought Rinka could stand up to her now, but the earlier lecture must have brought back guilt, throwing her off.

“Then, I’ll count on you, Brother.”

“Y-Yes…”

As I gave a wry smile in response, she might have noticed my pants pitching a solo tent.

—

Chapter 63: The Real Reason the Mistress Returned

“Come on, Brother. Come in.”

“Uh, excuse me!”

It’s been a while since I’ve been in Satsuna’s room, but it always looks like it belongs to a princess from some country.

Where did she even get that huge chandelier on the ceiling?

“By the way, Brother.”

She turned to me while putting down her stuff.

“I haven’t heard a single ‘welcome back’ from you yet.”

Oh, I forgot to say it.

If you noticed, you could’ve pointed it out earlier.

“W-Welcome back, Satsuna.”

“Yes, I’m back, Brother.”

…She’s so close.

Since Satsuna’s taller, being this close makes me feel even more looked down on.

That’s what being a refined lady is all about, I guess.

“So, Brother, don’t you have anything to say to me?”

Something to say…?

Besides greetings, what else is there…?

“Brother, do you really think I came back home just because Fuzuha called me?”

Huh, that’s not it…?

“Sigh. That face shows you really don’t get it. You’re as carefree as ever.”

Satsuna stepped away from me and sat on the bed.

“Brother, come here.”

I moved to the bed as told, about to sit next to her.

“Why are you trying to sit on the bed? Your head’s too high.”

There it is.

A phrase that always ranks high on lists of things guys want to hear from a girl.

Those online lists are way more trustworthy than TV.

“Your head should be about level with my feet.”

So, kneel, basically.

Yes, of course, I’ll do it!!//

I didn’t show any resistance and obediently knelt in front of her feet.

“So, you really have no idea why I suddenly came back home?”

No, I genuinely don’t know.

Back when Satsuna thoroughly tamed me, I might’ve figured out what my mistress was thinking, but now, after so long, I can’t guess at all.

“I see. If you had any self-awareness, there might’ve been some hope for you.”

Her words gave me a rough idea of the situation.

Satsuna’s even angrier at me than before.

“Uh, did I do something?”

I asked nervously.

“Well, fine. If you’re not aware, I’ll tell you. Brother, it seems you’ve made a completely inappropriate ‘girlfriend’ at school.”

What? How does she know!?

I can’t believe Fuzuha would snitch about that over the phone.

“That face shows you’re wondering how I know. Brother, look at this.”

Satsuna pulled several photos from her pocket.

How does she fit so many in her uniform pocket?

“Gah!?”

The photos showed me and Kirino-san walking to and from school, flirting in class, eating lunch together on the rooftop, studying together at cram school, and even going on a date arm-in-arm.

“It turns out, I have a few acquaintances at your school, and they sent me these.”

I can’t believe Satsuna had spies at Joto Nishi Prefectural High School…

“So… this woman next to you in all these photos. She’s your girlfriend, right?”

“Yes, that’s right…”

Since she’s figured it out this far, I can only raise the white flag.

“…What’s her name?”

“Kinui Kirino-san…”

“…Not a name I like.”

That’s beside the point.

“But to make such a shameless woman your girlfriend while I’m here.”

Kirino-san’s appearance isn’t shameless at all.

“…I’m deeply upset by your bad taste and betrayal, Brother.”

I glanced up at Satsuna’s face.

Yeah, she definitely looks upset.

Unlike the condescending look she gave Rinka, her face still has no expression, but her eyes are like a child whose toy was taken by someone else.

…I can somewhat predict what’s coming next and can only hold my crotch in response.