After being involved in a car accident together, Hajin was asked by Sihyeon to take care of Sihyeon's younger sister after her death. Hajin never thought that it would mean he would wake up in the hospital in Sihyeon's body, not his own. To make matters worse, Sihyeon is a famous idol who will do anything for money, has many sponsors, and will apparently leave the boy band she joined to sign a new contract with a bigger agency. Initially, Hajin believed in the public's negative opinion about Sihyeon, but the more he learned about Sihyeon's plight, the angrier he became. Determined to take revenge on Sihyeon's behalf, Hajin decides to ask an old acquaintance for help. However, the deeper he gets involved in his revenge plan, the more people become involved with him...