This was one of those couples that I was not used to seeing. I really had a hard time recognizing who they were. It was one of those deals, where I didn't even know a starting point on my brain to scratch. If you haven't read the manga, or seen the anime/live action, I would recommend it. It is quite funny, although if the characters in it are apparently not that memorable.
These two are Kou Ichinomiya and Maria. They live under a bridge in the Arakawa district of Tokyo. Thus the title of the anime. Hope you enjoy the photos!