Seong Gi-Hun (Lee Jung-Jae) gets fired from his job. His life is miserable. Seong Gi-Hun hears about a secret survival game, with a 45.6 billion won prize for the winner. He decides to take part in the game. Meanwhile, Cho Sang-Woo (Park Hae-Soo) is like a brother to Seong Gi-Hun and vice versa.