Trapped in the deadly cursed "Mafia Game," the students of Yoo-il High must play the game to survive, while unraveling the mysteries behind the curse.

Yeon Ho and Jae Min's high school graduation day. Yeon Ho runs holding Jae Min's hand. Suddenly, Yeon Ho apologizes to Jae Min for no reason, but Jae Min replies to Yeon Ho with a confession. Can Yeon Ho answer Jae Min's courage?