Toyo recently began living with her daughter and son-in-law, but while her own sexual desires remain strong, she's troubled by the complete lack of intimacy between the couple. One day, the family decides to go on a hot spring trip together, and Toyo seizes the opportunity, suggesting the couple have sex. However, as she talks, she becomes increasingly aroused herself. The couple has already left for the hot springs, leaving Toyo alone in the room with her grandson Tatsuya. Overcome by desire, Toyo gives in and reaches out to him.