When high school student Kaname Sudou receives an invitation link from his friend to play a brand-new mobile game called Darwin's Game, he has no idea that it would change his life forever. At first glance, the game looks like a regular fighting game. However, it has a dark truth—the battles are fought one-on-one, and the loser dies in the real world.

Not long after joining the game, Kaname is abruptly matched up against his first opponent. The odds are against him, yet he miraculously comes out victorious. Afraid of his new reality, Kaname attempts to find ways to exit the game and return to his daily life. However, the only method seems to be winning all the given battles. Kaname must now figure out how to stay alive and try to find allies he can count on.