Mio entered the family as the second wife and became Toshio's mother. During adolescence, Toshio did not accept Mio and his bad behavior became noticeable. Mio was devoted to becoming Toshio's mother, but Mio's body was too young, beautiful, and erotic to be called a mother. Toshio's homeroom teacher demanded her body in exchange for not expelling him, and Toshio's friend secretly photographed the scene. Using the photo as a pretext, Mio forced a relationship with him. Swallowing her tears, Mio decided to accept his despicable demands...