After losing his wife, father-in-law Yuzo moves in with his son. While his son is at work, he is left alone with his wife Yoshie. Yuzo is drawn to Yoshie's kindness and her large breasts that seem to be bursting out every time she cleans or does yoga as part of her extracurricular activities. Before long, Yuzo breaks the taboo of "stealing his son's wife" and violates her large breasts...