Unlimited Fafnir, originally titled Jūō Mujin no Fafnir (Jūō Mujin no Fafunīru), is a Japanese light novel series written by Tsukasa and illustrated by Riko Korie. Kodansha has published fifteen volumes from July 2013 to November 2017 under their Kodansha Ranobe Bunko imprint. A manga adaptation with art by Saburouta began serialization in Kodansha's seinen manga magazine good! Afternoon from March 2014 to December 2015 and is being published digitally by Crunchyroll in North America. An anime television series adaptation by Diomedéa aired from January 2015 to March 2015.