Yurine has discovered her husband's affair and is currently living separately from him with the intention of getting a divorce. When her son returns home to visit her mother, she meets him to tell him about the divorce. Her son has had feelings for his mother and presses her for a relationship if he will divorce her. Even though she knows it's wrong, she can't look away. Even though she knows it's wrong, she can't refuse. Her sense of guilt as a mother and the joy of being a woman are in conflict. The mother climaxes repeatedly every time her son thrusts into her with his penis, which has grown stronger after being touched by him. There's no going back... This is a story of incest that opens the forbidden door and continues to take place over and over again.