Ko Ichinomiya’s family motto is “Never be indebted to anyone,” yet after losing his pants and falling into the Arakawa River, he finds himself in debt to his savior, the delightfully eccentric Nino who lives under the bridge. To repay her, he vows to help Nino experience love. Along the way, he encounters the river’s other residents, a hot‑blooded kappa, a Sister in drag, and a literal rock star, each adding to the whimsical chaos of their unconventional community.