Although Yuka's libido gradually increases with age, she has been having no sex with her husband. One day, she finds out that her husband has been having an affair, and their relationship cools off. She is meeting her son to tell him that she has decided to divorce her husband. Upon hearing about the divorce, her son approaches Yuka. "No..." However, Yuka's resistance is futile. Her son mercilessly inserts his erect penis into her... Yuka is soon engulfed in a whirlpool of intense pleasure...