To care for her ailing father-in-law, Genichi, Rena had to move in with him. Genichi, who used to be a playboy, starts to see Rena as a woman while being cared for and ends up assaulting her. Unsatisfied with her sex life with her husband, Rena becomes hooked on Genichi's skilled techniques. Their relationship deepens, and they continue their affair during the day when her husband is not home.
