K-On! is a Japanese four-panel comic strip manga written and illustrated by Kakifly. The manga was serialized in Houbunsha's seinen manga magazine Manga Time Kirara between the May 2007 and October 2010 issues. It was also serialized in Houbunsha's magazine Manga Time Kirara Carat. A 13-episode anime adaptation produced by Kyoto Animation aired in Japan between April and June 2009.