Kai Ichihara is a high school student who receives a strange email asking him if he wants to try "Slave Go," a mobile game that will enslave certain people if they are "captured" by taking a picture of them. After using the app on two people, Kai is shocked to learn they have disappeared and the game he thought was just a joke must be real. Then when his good friend Rinna Date also vanishes, he fears she has met a similar fate. Confronted by a mysterious man named William Gotou, Kai is taken to a room where the slaves he captured are to participate in a death battle concocted by wealthy members of "Society," an exclusive, underground community. Betting is done through a currency called Delos and when one loses all their money, they will become a slave. Although he is able to win his first game, this is just the beginning, as Kai finds that Rinna has indeed become a slave, and in order to free her he must pay a fee of one hundred million Delos. With William acting as his guide, Ka