Kentaro, a college student, is a popular guy with a strong sexual appetite. He flirts with the women around him and has sex with them all the time. His mother is worried that he might get into trouble one day if he continues like this, so she orders him to spend the summer vacation at her parents' house in the countryside to reform him... But when her aunts, Satomiko and Chisato, hear that their nephew has a strong sexual appetite, they are intrigued and can't resist and start seducing Kentaro.
