Sana remarries and gains two stepchildren, gradually bonding with them as a family. But one day, her younger stepson Kenji secretly films her masturbating and confronts her, asking, "Are you unsatisfied with just Father?" Sana gives in and surrenders her body to him. Driven by rivalry, her older stepson responds by anally assaulting her and brutally imprisoning her in an abandoned building. Ultimately, the stepmother becomes sexually dominated by her stepchildren.