Yuki lives with his mother Yoshino (Hanoka Yoshino). Six years ago, his father passed away, and since then, Yuki has been well taken care of by Yoshino's younger sister Maki (Hojo Maki). Before he knew it, this had turned into romantic feelings. One day, Yuki was caught masturbating by Maki and couldn't hold back any longer, assaulting her. However, in turn, his mother Yoshino witnessed him having sex with Maki. What will happen to the three of them from now on!?
