After her divorce, married woman Ayumi is forced back into her ex-husband's home where he steals her money and repeatedly rapes her. Her stepson accidentally witnesses the abuse and erupts in rage, shouting, "You're still cheating even after three years? I might've forgiven you if it were your ex-husband!" He then begins to dominate her completely. Ayumi is stripped naked, forced to wear only an apron, and made to clean the house. While her husband bathes, she's subjected to relentless toy torture, gradually succumbing to her stepson's control and transforming into his obedient sex slave.