Sex Exchange

Sang-min is living in Hyung-min's house. One day, Hyung-min brings home his girlfriend So-mi and says she'll be living with her. So-mi looks younger than Sang-min and he witnesses his brother impose physical violence on her. Actually, Hyung-min had brought her home because she had nowhere else to go after the stocks crashed and he was paying off her debts. She'd put her hands on Bitcoin once again and he was only trying to persuade her out of it, but Sang-min had gotten the wrong idea. So-mi was sad and drunk and Sang-min ends up having sex with her. Hyung-min witnesses this, but pretends not to know. Sang-min slowly abandons his girlfriend, Jung-hyun, who comes to his house because she can't get a hold of him. Alone at home, Sang-min tells her about his relationship with So-mi and makes a secret suggestion.

The secret story of the sexiest and youthful sisters that can not be revealed! The confidential secret of the boyfriends who reveal is revealed. He is a sister. Sukyoung is between Sangwoo and Jinhee and loving each other. The two of them talk about their lover, and when they accidentally find out that their boyfriends are high school alumni, they ask about her sister's boyfriend ...