Marie is a young wife who married a man much older than her. She wants to build a good relationship with her stepchild, Naoki, who is the same age as her, but it's not going well... Desperate for help, Marie consults Naoki's friends and learns an unexpected truth. That night, as they talk in Naoki's room, Marie is carried away by Naoki's complaints about the loneliness of being a single parent and ends up accepting his twisted desires. However, it was a trap set by Naoki, and with her weakness exposed, Marie has no choice but to obey without telling her husband...