With her husband transferred away for work and her son living with him, Rin enjoys living alone as if she were single. One day she discovers that Takuto, her mom friend's adult son, is also her part-time coworker. Frustrated by a sexless life, Rin becomes interested in his muscular body and secretly invites him for drinks alone. The two begin an affair limited to their work shifts, repeatedly stealing thrilling encounters wherever they can during working hours. Each time Rin clocks in, her body instinctively begins to ache for him.