Mai is unsatisfied with her sex life with her boyfriend, who she is thinking of marrying. When her frustration reaches its peak, she ends up having a physical relationship with a kind man who attends her swimming lessons. It was meant to be just a one-time affair, but before she knows it, her body is no longer with him, and begins to crave his lover. After the lesson, in the empty pool, she loses herself in moaning and groaning as she repeatedly climaxes with the beautiful, slender instructor, who has a young, toned body and an incredible figure.