On the weekend, the younger brother decided to go from his hometown to the city to visit his brother's family because it had been a long time since they met. It was the same day that his brother had to go on a business trip away from home, so only he and his sister-in-law Saeki with fair skin remained. Here he accidentally saw the scene of his sister-in-law masturbating in the bedroom and recorded a video, perhaps because her brother often went to work far away and could not make up for her feelings, so she had to do it to satisfy herself. Because he didn't have a lover, he was very curious about it, so he boldly threatened his sister-in-law, forcing her to have sex with him or else he would show his brother that depraved video. Apart from accepting to follow, Saeki could not do anything more, it partly helped her relieve her emotional deprivation during her husband's business trip.