Miyu's older brother is a gentle, laid-back pervert who gets excited over the smallest things. Because of his physical limitations, he needs Miyu's help changing clothes, but he instantly gets a hard-on every time, even going so far as to wash her gym uniform along with her body. During recorder lessons, he can't hold back—he peeks at Miyu masturbating but can't climax easily, then uses a vibrator to give her swimming lessons. Miyu finds herself getting turned on by her utterly perverted brother, whose bizarre behavior makes no sense no matter how you look at it.