Arakawa Under the Bridge

Ichinomiya "Riku" Kou, a young upper-class man who tries to live a life without any debts to anyone, and a strange yet beautiful homeless girl called Nino who claims to be from the Venus. Unfortunately for him, he ends up owing his life to Nino and has no choice but to live with her under the bridge by the Arakawa river in order to follow his debt-free policy.