Denpa Onna to Seishun Otoko (電波女と青春男?, literally "Electric Wave Woman and Youthful Man", "Denpa" or "Electric Wave" being used in Japanese to refer to a person who is crazy or holds odd beliefs, similar to the English term "Tin foil hat") is a Japanese light novel series written by Hitoma Iruma, with illustrations by Buriki. The series includes eight novels released between January 2009 and April 2011, published by ASCII Media Works under their Dengeki Bunko imprint. A manga adaptation started serialization in the October 2010 issue of ASCII Media Works's Dengeki G's Magazine. A 12-episode anime adaptation began airing in Japan in April 2011.
Makoto Niwa meets his first cousin Erio Tōwa at the house of his aunt Meme Tōwa. Erio is no longer enrolled on the register of the school and wears a futon. Erio claims that she is an extraterrestrial life.
Denpa Onna to Seishun Otoko began as a series of light novels written by Hitoma Iruma and with illustrations provided by Buriki. Eight novels were published by ASCII Media Works under their Dengeki Bunko imprint between January 10, 2009 and April 10, 2011. One extra volume titled Denpa Onna to Seishun Otoko SF (Sukoshi Fushigi) Han (電波女と青春男 SF（すこしふしぎ）版?) was published on April 10, 2011.
A manga adaptation, illustrated by Masato Yamane, started serialization in the October 2010 issue of ASCII Media Works' Dengeki G's Magazine.
An Internet radio show to promote the anime series and other Denpa Onna to Seishun Otoko media called Denpa Mail to Seishun Radio (電波メールと青春ラジオ?) began streaming online on April 7, 2011. The show is hosted by Asuka Ōgame, the voice of Erio Tōwa in the anime, and is produced by Animate TV.