Kyousuke ended up staying at his brother's house for two nights due to work. He was at a loss as to where to look because of his sister-in-law's beauty and lewd demeanor. On the first night, Kyousuke woke up in the middle of the night and accidentally saw his brother and sister-in-law having perverted sex. On the second day, after his brother told her he wouldn't be coming home that night, his sister-in-law said to Kyousuke, "I want you to train me."
