Sisters' Tasty Swapping.

Hee-soo goes to her ‘rich lover Seok-ho’ while her husbands is on a business trip. Her younger brother Hee-yeong and her husband Jeong-tae are also together. Hee-soo introduces Seok-heo to Hee-yeong and Jeong-tae, and Seok-ho falls in love with Hee-yeoung at first sight. As Seok-ho tries to avoid Hee-soo’s eyes, and meet with Hee-yeong’s eyes instead, he decides to take advantage of Jeong-tae. Jeong-tae who dreamed of having sex with Hee-soo, seduces her, and while Hee-soo and Jeong-tae were playing, Seok-ho wins and took Hee-yeong as price. These people who are complicatedly intertwined, are at a crossroads to choose whether to disperse or become a new family.