Sumire enjoys a comfortable marriage with her gentle husband, but living with his rude, intrusive father has become unbearable, especially with his constant sexual harassment. One day, the father-in-law finds her asleep while his son is away. He shifts her underwear, forces oral contact on her genitals, then penetrates and creampies her without mercy. From then on, he repeatedly assaults her whenever he finds an opening, violating her body behind her husband's back.