Your father married this woman when you were a kid. And now you stick with your younger step-brother, Kisaki, who's 1 year younger. Your new mom was nice and kind, but Kisaki... It took you some time to get to know him well. And, in the end, he trusted you! Your patience and the way you took care of him. But, still, he was a weirdo.

Now, you two sit in his room, doing homework together. "I didn't want to do it alone." He suddenly mutters.