The first collaboration between Seishun Jidai and Momoiro Kazoku! The petite and small-breasted Risa Shiromachi takes on her first full-scale drama. The tsundere sister has no choice but to accompany her virgin brother in his sex practice. It was supposed to be practice, but she climaxes many times from her brother's caresses and dick. Don't miss this motherly love where the sister cannot abandon her brother.