An Affair: Kind Daughters-in-law 3: Seok-joon has two sons; Min-seok, who is married, and Yoon-soo, who is not. Seok-joon tells them he is going to give allowance and his wealth to his daughters-in-law only. Yoon-soo asks one of his lady friends to get married for Seok-joon's money. Min-yeong and Yoon-jin pretend to be Yoon-soo's girlfriends. Then Yoon-jin falls for Seok-joon. The women visit the house often to get on Seok-joon's good side, and so does Yoon-soo's ex-girlfriend, Min-yeong. However, Seok-joon falls in love with Yoon-jin, and Yoon-soo is very disappointed in Seok-joon, who wants to start a new life...