When his wife Takako becomes pregnant, her mother Mihana comes to the city to help with cooking, laundry and housework. As the marriage deteriorates, Takako even forbids her husband from masturbating. After watching him suffer for a week, Mihana gently touches his crotch and says nobody prohibited her from giving him a handjob. From that day on he cannot stop thinking about her, and the sight of her ass while she cleans finally pushes him into repeated breeding sex.