For most humans, death leads to either Heaven or Hell. However, a select few are brought to Quindecim—a bar accessible only to pairs of people who die simultaneously. The establishment is attended by an enigmatic figure named Decim, who serves as the arbiter. He judges those who arrive at Quindecim by challenging them to life-threatening games. The outcome of these games determines whether the patron's soul will reincarnate into a new life or be cast into the void, never to be seen again. Through activities ranging from darts and bowling to fighting games, the true nature of each patron is gradually revealed as they wager their souls. Although his methods remain unchanged, the sudden arrival of a black-haired amnesiac causes Decim to reconsider his own rulings.