In the story, we follow the main character Min Ji-won, who suffers from amnesia, caused by an accident almost a year ago. While the "new" Min Ji-Won is a shy person, who dislikes fish soup. We soon learn, that her past was totally different. Before the accident she was the leader of a gang of four bullies. Through pictures, she learns about her 3 other "soul mates" and she wants to find out what happened to them. Whilst Min Ji-Won tries to unravel the mystery, her former friends are killed one by one. Min Ji-Won has little time left to find out what happened to her and the mysterious Su-In.