It was a tennis circle recommended by a mom friend to eliminate lack of exercise, but as soon as she started going, Reika, a married woman, became friendly with the coach rather than playing tennis. For a married woman with time and sexual desire to spare, there is no need for troublesome intrigues and she easily falls into a physical relationship with the coach. And the next day, she brings the coach in while her husband is not home and indulges in a physical relationship. The manager, unaware of all this, is secretly watching Reika's every move...