Mai enjoys a comfortable marriage with her dependable husband, but she hates having to live with his vulgar father. The man suddenly moved into their home and refused to leave. One day, he finds Mai asleep while her husband is away and takes advantage of his son's absence, pulling aside her underwear and devouring her sweat-scented pussy. Having gotten a taste, her father-in-law assaults Mai however he pleases almost every day and treats her like a sex slave.