Yumi has been married for 10 years. Her husband has been busy with work recently, and the couple's nightly activities have become almost nonexistent. Before long, she finds herself masturbating alone on the sofa. One day, her husband invites her subordinate, Tanaka, over to their house. Yumi, who is talking to an energetic young man for the first time in a while, is unable to suppress her growing arousal and leads Tanaka to the bedroom behind her husband's back...