Kou Ichinomiya is the son of a rich CEO who has lived his life strictly to never be indebted to anyone. However, when some young punks mysteriously rip off his pants and hang them on a high part of a bridge, Kou plans to go retrieve them himself when a mysterious girl offers helps him bring them down. He refuses and tries to climb up and grab them himself, but ends up falling into the Arakawa river where he nearly drowns until the girl dives in and saves him.
2) Under a Star-Crossed Bridge
Kou is absolutely terrified of the fact that he has now become indebted to the girl for saving his life, so he tries to find a way to pay her off. When he offers to move her into a brand new home, she refuses. After nearly having an asthma attack, Kou demands to know what she wants in return, and the girl proposes that Kou become her lover.