一个单身汉渴望结婚，却总是被女人拒绝。为了赢得曾经暗恋女孩的芳心，他接受了意料之外的帮助，而这竟然是来自女孩的母亲
崔亨旭（刘海镇 饰）是一名经验丰富的杀手，凡是交给他的任务，他总是能够完美的将它们完成。某日，在干了一票大买卖之后，崔亨旭来到大众浴室洗澡，哪知道竟然因为踩到了肥皂摔倒，陷入了昏迷之中。此时，一直在边上暗中观察他的无名演员尹在成（李准 饰）偷走了崔亨旭的手牌，将他柜子里的财务据为己有。 在医院醒来的崔亨旭失去了记忆，凭借着被交换过的手牌，他以为自己是尹在成，两人就这样在阴差阳错之下交换了身份。为了生存，崔亨旭开始打零工，因为在片场展现出了出色的身体素质和格斗技巧，而受到了导演的赏识。那边厢，尹在成发现了崔亨旭的杀手身份，并且对他的下一个目标宋恩珠（林智妍 饰）产生了感情。
Chan-woo, who has been studying to become a police officer for 5 years, joins his friends for dinner to ask for the money to apply for his exam and ends up getting drunk. He completely blacks out and wakes up not remembering what happened in his next door neighbor's room. Not only that, he finds a bloody corpse in the middle of the room. He hurries back to his room and tries to...
