A young couple, Takashi and Machiko, arrive in the bar Quindecim without any recollection of how they got there. The bartender tells them they cannot leave until they first finish playing a game, one in which their lives will be at stake.
A black-haired woman awakens in an unfamiliar place, unable to remember even her own name. She is taken by a girl named Nona to Quindecim, where she is told that she will be an assistant, and is instructed as to the purpose of the bar's existence.
