Raito Mashiko

Riku, the heir to a corporate conglomerate, is determined to go through life never owing anything to anyone on principle. However, one day he nearly drowns in a river and is saved by a homeless girl named Nino. To repay his debt, he begins living together with her on the banks of the river as her lover.

Kou Ichinomiya has always lived according to the creed of his wealthy, successful family: never be in debt to anyone. But one day, under the Arakawa Bridge, his life is saved by a homeless girl named Nino. In order to pay her back, Kou promises to be her boyfriend; and thus begins his new life under the bridge.