Rich Man Exchange Sex: Joo-won lives with his father Tae-jin and his father's lover So-young. The father, who is the boss, keeps the girl he likes with his own money, but it is not very long. Although such a father is not greedy, he simply passes on because he receives a lot from his father who is capable of that. Joo-won invites his girlfriend Ji-soo to the house and introduces him to his father. On the outside, Tae-jin pretends to be kind, but his eyes are getting more and more insidious.