Yuuki lives with his mother Yoshino (Hanaoka Yoshino). Her father passed away six years ago, and Yuki was often taken care of by Yoshino's younger sister Maki (Hojo Maki). Over time, it turns into love. One day, the courage that Maki saw masturbation can't stand it and attacks her Maki, but on the contrary, her mother Yoshino sees sex with her Maki. What will happen to the three of them after that?! ?
