Ui-gang is a retired hitman. While his wife goes on a trip with her friend, she asks him a special favour to take care of her friend's daughter. He doesn't want to be bothered by the teenage girl, but Yoon-ji gets stuck with juvenile delinquents, and Ui-gang unavoidably uses a little bit of violence to protect her. However, strangely, the juvenile delinquents are found dead, and things start to get serious. Even worse, Yoon-ji is kidnapped by a teenager trafficking unit and Ui-gang is suspected of murder. He cannot fail his wife; he must get Yoon-ji back.