Three years into their marriage, Yu feels a slight dissatisfaction with her bland husband but maintains a harmonious married life. One day, her brother-in-law Ken'su, an exercise trainer, visits their home. Recently, Yu has been concerned about her sagging body and, at her husband's suggestion, decides to receive guidance from him… However, unlike her husband, the carnivorous Ken'su is excited by Yu's massive breasts from the moment he sees them and uses the pretext of guidance to fondle her voluptuous body. Soon, unable to resist the allure emanating from Yu's heated body, he grabs her breasts tightly…
