After fighting with her husband, Azusa Tani shows up at his brother's home in the middle of the night and pushes her way inside. He reluctantly lets his sister-in-law stay for a few days, but her constant closeness leaves him tense and visibly hard. When she notices his erection, she offers to get him off in return for taking her in, then seduces him into raw sex and creampies from morning to night.