Poong-Ho (Lee Joo-Seung) ganha a vida lutando. Seu irmão mais velho, Kang-Ho (Lee Jung-Jin), é um detetive respeitado. Quando durante uma investigação Kang-Ho é morto em uma luta seu irmão decide buscar vingança.
Changsu does not have any family, friends or lover living in prison as a substitute prisoner for the others. After 3 years in prison, he came back to his normal life with gambling and drinking. One day, Miyeon, appears to him, and everything changes. She enlightens his life for the first time. Changsu bets his everything to save this woman for the first, and for the last time in his life.
Four friends pledge to commit suicide together but while standing on the ledge, only one of them actually jumps. Her ghost begins to haunt the remaining friends until the pledge is fulfilled.