Female college student Nam Da-jeong (Kim So-eun) is from a poor family. Her father abandoned her daughter and ran away because he was in debt and unable to repay. However, Nam Da-jeong is kind and simple by nature. She always trusts others easily and unconditionally. Unexpectedly, this kind of character makes her involved in a fraud game designed by Kang Do-young (Shin Sung-rok). Although winning the game can bring Nam Da-jeong a large bounty, once she fails, she will also be burdened with a huge debt. Nam Da-jeong, who is young and inexperienced, loses to her once respected teacher at the beginning of the game. In desperation, she finds the genius fraudster Ha Woo-jin (Lee Sang-yoon) who has just been released from prison, hoping that he can help her win back. After seeing Nam Da-jeong's innocence and persistence, Ha Woo-jin, who can't just sit back and watch, joins the game.