Yu is a housewife who joined a tennis club on the recommendation of a mom friend to get some exercise, but she ends up getting closer to the young coach than to the tennis itself. With too much free time and an overflowing sex drive, she skips the tedious flirting and easily brings the coach home to fall into a physical relationship. Naturally, such a sweet affair doesn't end with just one time; the very next day, in broad daylight and without her husband's knowledge, Yu brings the coach over again to drown in their physical passion. All while completely unaware that the building manager is peeping on them...