Tae Gun-ho (Jung Jae-young) is a professional debt collector. His painful past has made him extremely cruel, and he will do anything to complete his work. One day, the doctor diagnosed Tae Gun-ho with liver cancer. He has not much time left, and the only way to save his life is to undergo a liver transplant within ten days. Tae Gun-ho has locked onto a woman named Cha Ha-won (Jeon Do-yeon), or more precisely, her liver. However, Cha Ha-won is currently behind bars for fraud. Tae Gun-ho finds Cha Ha-won, who agrees to transplant his liver, but Tae Gun-ho must help her find her master Cho Myeong-sik (Lee Kyung-young), who framed her for imprisonment. She only has revenge in her mind. The two people, who are not good men and women, formed a strange partnership based on interests, but a wonderful relationship developed.