6 My sister is a yandere

Arisu Sakayanagi POV

My brother suddenly changed.

He was supposed to be back home early after the school bell rang, but now? He comes home late, and even our sexual activity has greatly reduced because of it.

If there's nothing suspicious about it, I wouldn't believe it.

My brother is a pervert. As soon as he gets home, he would use my body to relieve his high libido. It's just rubbing, not sex, as the servants are still at home and probably would hear us if we were too loud.

Now, he only does it at night and it's not as enthusiastic as before.

Moreover, I smell another scent on my brother's body that doesn't belong to him. It's not his scent; I'm sure of it. I believe he is cheating on me and having sex with another woman or forming a relationship with them.

And I really did take action and investigate the source. I wanted to see who the woman seducing my brother was. So, I visited his school under the pretext of losing my phone. I asked him about my phone's whereabouts, using that as an excuse to visit his class. While I was there, I took the opportunity to talk to some of his classmates about how he's doing in school. They said he's still a loner and never talks to anyone in class.

It's easier for me to take drastic action and make everything clear by talking to their headmaster and bribing him, but if I do so, father would discover our relationship by the fact that I care too much about who my brother interacts with.

However, if I ask harmless questions, it's what a normal sister would do—caring about their brother's social life. But if it gets to the point of stalking, it's not normal sister behavior, but rather perverted.

That's why, after asking, I left. When I asked my brother about the scent of another woman on his body, he would assert himself and make a mess out of me in an instant. He would stuff his penis inside me and not play it safe as before, just pure roughness that makes me subconsciously cover my mouth with my hand and have no time to ask him until he makes a bloody mess out of me.

Even if I tried to drain him, he was stronger than me in every way and it didn't work; he was still late as usual.

If this continues, he would be stolen away from me, and I know it.

"So, brother, can you introduce me to your girlfriend?" I asked bluntly, acknowledging the fact that my brother is cheating.

"I don't have one," he answered casually.

"So, it's a sex partner?" I asked sharply.

He didn't answer and refused to do so.

The main reason I believed him when he said that the person entering his life wasn't a girlfriend was because my brother is usually very honest. This honesty isn't due to virtue, but rather because of his pride. He often chooses not to answer questions he doesn't want to answer, rather than lying.

He has always been like that, refusing to let other people take part in his life or enter his heart. That's why he would never accept anyone as his girlfriend or the love of his life. Even I am no different; he never shares anything with me—his happiness, his sadness, his personal life, everything is kept hidden.

I don't like him having casual sex with other women and gripped my brother's hand in anger for cheating on me, my nails piercing through his flesh. Even when he saw the bleeding mark on his hand, he didn't make any retaliatory move.

"Are you satisfied, Arisu? If this could make you lash out all of your unhappiness, so be it, but I will do what I want," he stated.

Meaning he wouldn't stop what he does, but he wouldn't stop me from stopping him either or lashing out my unhappiness at him.

I kissed him forcefully and bit his lips until they bled. Now, we knew our relationship would never be the same again; our sex was no longer gentle but rough and on the brink of threat, as I would do a lot of biting. And he just stroked my hair as I vented.

"You've won, brother," my anger was replaced by pure calmness as I stared at my brother while straddling his chest. "I will close my eyes to what you did with your sexual partner. However, can you at least introduce her to me?"

"Even if I had one, do you think she would willingly follow me to an isolated school like ours that we will attend later?" he asked rhetorically.

I was at a loss for words. He was right; it is impossible for that woman to be willing to follow my brother willingly to a school that is essentially isolated from the outside world, despite the guarantee of acceptance at any job they might choose after graduation. After all, people who want to keep in touch with their families or maintain friendships in the real world would choose a different school.

Moreover, his personality alone is a huge turnoff for most women. I know my brother's personality better: he is an outright egoist, jerk, and menace. He possesses many negative traits that are enough to repel most people on the planet. He never prioritizes the well-being of others above his own. He cares only about himself. As long as the other party annoys him or oversteps, he shows no hesitation in retaliating violently.

Probably, that woman just finds my brother physically attractive and doesn't mind having a sexual relationship with him.

However, this doesn't mean I fully believe my assumption. Further investigation is still necessary. I will let it go this time if it is really so, but if she does follow my brother to the school that is supposed to be our two worlds, I will have her drop out without hesitation. That's all. I don't want to make any more unnecessary moves that could provoke my brother's anger by taking things too far.

As much as I hate to admit it, my brother is very scary when angry. He shows no regard for excuses or opinions from those who oppose him or stand in his way. When provoked, he either humiliates them or resorts to extreme violence. Even back in elementary school, when someone tried to bully him because they saw him as an easy target due to his loner status, he did something no one expected. He threw the bully into the pond during a religious activity, nearly causing them to drown and die. This incident traumatized them greatly, and from then on, everyone feared my brother. He shows no mercy to anyone or anything that challenges him.

So, I don't dare to provoke him or push him to show his full strength because when he's provoked or motivated, he surpasses me in every way. While he remains unmotivated, there's some flexibility in my plans regarding the woman who's trying to seduce him, but I won't push it too far unless absolutely necessary.

I have a better plan, a better way to make my brother not only love me more but also make him hate that vixen at the same time.

...

Genji POV

After waking up from my sleep, I stroked my sister's hair gently.

Since that day, she became more submissive and active. In the past, when I wanted to finish inside her, she would stop it.

But now? Yeah, I finish inside her a lot until her stomach bulges like in a hentai comic. I mean, this is anime, so the sexual scenes are over the top.

If it followed our previous life's logic, you would get cuckolded for sure. In anime and hentai, women are prone to big dicks and rough sex, or whatever they're called. As long as it follows hentai logic, you will not get cuckolded, and your woman is satisfied. That's anime logic for you.

The previous refusals of blowjobs and anal are nonexistent as we explored that territory more.

Moreover, she initially liked the cowgirl position, but after that incident, she lets me do more of what I like and more doggy style as I fuck her from behind like a stallion while gripping her hair.

Because of this, I paid more attention to my sister than Kei, as Arisu became much more submissive than Kei, and I loved every minute of it. The power and control I have over Arisu make me prefer her over Kei.

However, I know that it only applies to sex and only temporary. Outside of it, she still holds an aggressive attitude and is dominant.

The temporary meaning is: when she takes back control of the narrative, she will be back as her usual self, despite knowing that her acting submissive was to let my guard down and make me unmotivated to fight against her. I let her be.

I know myself better. I am an embodiment of negativity and menace. I have many shortcomings, and people who see through my true nature will be repulsed by me. That's just who I am. I don't know how many people have left me in the past due to their inability to accept me for who I am. Not once or twice, but over and over again, people only focus on my flaws, disregarding the positive traits I have or the help I have provided them in the past. They care only about the mistakes I have made. This is why I have become uncaring, selfish, and have developed sociopathic tendencies, no longer trying to please others or seek their acceptance. I am who I am, whether they like it or not.

On the other hand, my sister knows the best of me, even if it's not everything (or all). This is the best reason why I can tolerate her anger towards me.

She accepts my shortcomings, even knowing I was cheating behind her back. She didn't leave me; instead, she fought tooth and nail to retain me and get rid of all her rivals. She is very cute indeed.

I hugged my cute sister as I softly patted her head.

"What is it, brother?" she asked me with confusion.

"Nothing. I just feel you've become cuter lately," I praised.

She hugged me back in response to the compliment.

"Don't think that I will forgive you because you complimented me, brother."

"Of course, my cute sister. You're free to loathe me however you want," I grinned with a twisted smile on my face.

So, that's how it is, folks, the twist of my life and my twisted relationship.