The remarried husband is busy, and the stepson is a hikikomori... 'Yukari,' who is happy but also lonely after marrying her beloved, witnesses her stepson Hiro's masturbation. Unable to hide her shock and excitement at seeing his young, erect penis, 'Yukari' retreats to the toilet and comforts herself with self-pleasure. Learning that the reason her stepson is a hikikomori is because he was rejected by a girl, 'Yukari' decides to teach him about women's bodies step-by-step to help him overcome his trauma. 'Yukari,' who has been sexless with her husband, finds it endearing when her stepson awkwardly touches her body and eventually shows her feminine side. As they engage in intercourse, 'Yukari' finds the young and hard penis of her stepson, who is frantically thrusting his hips, incredibly pleasurable. She becomes engrossed in sex with Hiro, who is eager to learn, and regains her femininity. 'Who feels better, Dad or me?' 'Hiro's dick is the best～!' Driven by a sense of taboo, the mother and son indulge in each other's bodies day after day, ultimately crossing the boundary between parent and child in forbidden incest...
