Wikipedia
is a Japanese light novel series by Akinari Matsuno, with illustrations provided by the group QP:flapper made up of Tometa Ohara and Koharu Sakura. Media Factory published 12 novels under their MF Bunko J imprint between February 2007 and September 2010, including two side story volumes. The series was left unfinished due to the author's death on April 18, 2011. A manga adaptation by Issei Hyoju was serialized between the September 2008 and February 2012 issues of Media Factory's Monthly Comic Alive. A drama CD adaption was released by Edge Records on March 24, 2010 and its first-press limited edition came with a bonus CD. A 12-episode anime adaptation produced by Xebec aired between October and December 2010. Sentai Filmworks released the anime series on English-subtitled DVD in North America in September 2011, and then re-released it in February 2014 with an English dub on both DVD and Blu-ray.