Rei Mizuna plays a seemingly demure wife who is secretly a former sex worker. Someone gives her a remote-controlled vibrator and teases her with it right in front of her unsuspecting husband. Unable to hold back, Rei slips into the bedroom to masturbate, only to be watched by her husband's friend. Realizing he can see her excites her even more, and once she crosses the line, she can no longer hide her true lustful nature or the filthy sex she craves.