Yuko realizes that her son has feelings for her that go beyond those of a mother, as he has seen her masturbating in his room and made her the protagonist in his erotic novel. She discusses this with her friend Reiko, but she learns an even more shocking truth from her. Reiko has also been seen masturbating by her stepson, and they have even ended up having a physical relationship. Taking Reiko's words "A mother is someone who accepts everything" to her heart, Yuko finally has a sexual relationship with her son, but...