Yuriko is an ordinary housewife. However, she has a secret that she cannot tell anyone. Her son forced her to have a physical relationship with him. At first, Yuriko thought it would be just a one-time thing, but her son didn't think so and kept coming on to her, so she gave in to temptation and continued the relationship. Realizing that this wasn't good, she begged her husband to have sex with her at night, but he refused, saying, "I'm tired." She started masturbating to release her frustrated feelings, but her son found her...