Misa is a housewife living with her husband and her working son. After reading an article in a magazine about how sexual activity keeps you young, she starts masturbating. Misa has a tendency to squirt, so she wets the tatami mat. When her husband sees the damp tatami mat, he notices and has sex with Misa for the first time in a long time. When her son comes home from work, he sees his parents having sex. One day, the son is drinking in the living room. Misa is talking to him. The drunk son lies on top of his mother and reaches for her crotch. Misa squirts when her son fingers her...