Kou Ichinomiya has always held up his family's tradition of never being indebted to anyone. While trying to retrieve his pants from a bridge pillar, they fall, dragging him down into the river, where he is saved by a strange girl named Nino. Suffering from an asthma attack induced by being indebted to Nino, he accepts the only way he can pay her back; by falling in love with her. In keeping with this promise, Kou feels obligated to live with her under the bridge. After a cold night sleeping in 'the villa', Nino takes Kou to the Village Mayor, a strange man dressed in a kappa suit, who gives him the name Recruit. Kou soon finds that Nino's room is a lot better than the villa, although he is quick to notice Nino's bizarre sleeping habits.