My father-in-law lives with his son and his wife... His son's wife, Norino, is kind, beautiful, and hardworking, and he is constantly relying on her for things like taking him to and from the hospital. Ever since he found out that his son's wife secretly masturbates in between housework, his father-in-law has been feeling hot inside, even though it pains Kokoro. His son, however, seems unable to satisfy his devoted wife in the sex life. Feeling sorry for her, the father-in-law can't help but do the forbidden act...!