is a Japanese manga created by Suzuhito Yasuda that began publishing by Kodansha in 2006, and was then published in the US by Del Rey in 2008. The series was animated in Japan and aired from October 2 to December 18, 2008; it comprises 12 episodes, all of which have aired. The anime was produced by Nomad and aired on TBS on Thursdays. Three anime OVAs (original-video-animation) were released alongside volume 9-11 of the manga, between October 10, 2010 to November 9, 2011. A new anime adaptation of the series aired in 2013, with the cast returning from the first anime and OVAs, it was produced at Tatsunoko Production. Another set of OVAs, adapting the Tsuki ni Naku arc (volume 11 of the manga), are being released with the special editions of volumes 14-16.