Arakawa Under the Bridge (荒川アンダー ザ ブリッジ – Arakawa Andā za Burijji) was originally a Japanese manga series written and illustrated by Hikaru Nakamura. The manga was initially serialized in the Japanese seinen manga magazine Young GanGan on the 3rd of December 2004. An anime adaptation produced by SHAFT studios and directed by Akiyuki Shinbo was green-lit with its first episode airing on April 4th, 2010 and the last episode airing on June 27th, 2010. The anime had 13 episodes and had a second season aired in Japan on October 3rd, 2010 until December 26th, 2010. The comedy anime is reminiscent of Hayate no Gotoku in a sense that the show is filled with weird characters.
The premise of the story is in Arakawa, Tokyo where Kou Ichinomiya, a man who was able to accomplish everything without relying on others accidentally falls down the Arakawa River. However, thanks for a girl named Nino (Arakawa); he was rescued from almost drowning and though his father taught him ever since he was little that he should never be indebted to anyone, he knew that he owes his life to this girl.
Because of this, he asks Nino in what way he could repay her so as not to be indebted to her and though it took a while before she could think of an answer, she eventually asks Ichinomiya Kou to love her. Unable to refuse, he later found himself living underneath the bridge and at the same time, eventually meets the strange denizens who live underneath the bridge.
There is the village chief who is a self-proclaimed 620-year old kappa despite the fact that he is obviously wearing a green kappa costume. There is also Hoshi who is a 24-year old singer and a self-proclaimed superstar and wears a star mask. There is 29-year old Sister (Arakawa)who is a war veteran but dresses like a nun and always carries a gun with him. As the series progress, Ichinomiya Kou gets to meet stranger characters.
Source: Zerochan; written by l_i_z