Deep in the labyrinthine alleyways of Tokyo, the Daybreak Detective Agency can be found. As the owner of the business, Waki Douchin attends to the request of a new client, Morishita Izumi. After the demise of his wife, Morishita hopes to find a man named Hoshihiko, whom he ran into 30 years ago in a strip club. Waki begins his lone search for Hoshihiko in a hot spring town—the place where Morishita and the mysterious man first and last met.

The trail seems to have gone cold after the passing of three long decades. However, during his quest, Waki experiences a series of peculiar events, which may ultimately point him toward Hoshihiko's current whereabouts.

[Written by MAL Rewrite]