Denpa Onna to Seishun Otoko - 01
"The story revolves around a highschool boy named Niwa Makoto. He lives with his aunt’s family since his parents are away on business. It is there where he meets his mysterious cousin of the same age Touwa Erio ― who happens to tie a futon mattress around her upper body and is a self-proclaimed alien."

Crazy moe.

Amusing. "Origins of the Penrose Four-Dimensional Twisted Life"? Did she really read those books? I need to see another episode.