Her remarried husband is busy, and her son-in-law is a recluse… Yukari, who is happy with her beloved but feels lonely, witnesses her son-in-law Hiro masturbating. Yukari, who is young and unable to hide her agitation and excitement over his erect penis, secludes herself in the bathroom and soothes herself by masturbating. When Yukari learns that her step-son’s withdrawal was due to him being disliked by girls, she decides to teach him how to use women’s bodies in order to overcome his trauma towards women. Yukari, who had not had sex with her husband, found herself smiling at her son-in-law, who was awkwardly touching his body, and eventually showed a woman’s face when she saw him leaning forward. “Yukari” is joined by raw penetration, and her stepson’s young, hard cock is irresistibly pleasant as he violently shakes his hips, and is asked by Hiro-kun, who is absorbed in the sex he has just learned, and regains his womanhood. “Which feels better, Dad or me?” “I like your dick, Hiro!” Driven by a sense of immorality toward her husband, mother and son love each other, devouring each other’s bodies day in and day out. With forbidden incest, the barrier between parent and child has been crossed…