Saki, a married woman troubled by concerns over her stepson's upbringing, notices he has been frequently purchasing suspicious adult goods online. Peering through the crack of his bedroom door, she sees him eerily caressing a lifelike love doll. That day, her son's homeroom teacher arrives with a female student, revealing that her son has been stalking the girl. Fearing he may become a sex offender if his behavior continues escalating, Saki decides to intervene. To suppress his uncontrollable sexual urges, she proposes using her own body as a masturbation aid, offering herself to satisfy his desires. "Use your stepmother's big tits instead—squeeze them," she tells him, sparking both shock and curiosity in her son. Accepting his rock-hard cock, Saki begins assisting in his sexual release, plunging into a twisted daily routine. This act becomes a disturbing expression of maternal love aimed at controlling his lust, portraying the bizarre, intimate relationship that develops between them.