Based on the light novel series by Takaya Kagami, with illustrations by Saori Toyota, which was published by Fujimi Shobo in Dragon Magazine from February 20, 2002 to October 20, 2006, and has 11 volumes.
The first episode was screened during a promotional event on June 26, 2010 in Tokyo. Participants were chosen amongst people who registered for the anime's e-mail newsletter. The actual television broadcast started on July 2, 2010.
The original light novel has a sequel, The Legend of the Great Legendary Heroes (Dai Densetsu no Yuusha no Densetsu) began publishing on October 20, 2007, and has been collected into 17 volumes.
The original light novel has 2 spin-off series, The Legend of Legendary Heroes Anyway (Toriaezu Densetsu no Yuusha no Densetsu), a collection of short stories which ran from December 20, 2002 to June 20, 2007 and was compiled into 11 volumes, and The Legend of the Black Fallen Hero (Ochita Kuroi Yuusha no Densetsu), which ran from December 20, 2007 to August 20, 2013 and was published in 8 volumes.