K-On! season 1

The first season of the K-On! animated television series is based on the manga series of the same name written and illustrated by Kakifly. The episodes, produced by the animation studio Kyoto Animation, are directed by Naoko Yamada, written by Reiko Yoshida, and features character design by Yukiko Horiguchi who based the designs on Kakifly's original concept. The story follows four Japanese high school girls who join their school's light music club to try to save it from being abolished. However, they are the only four members of the club, one of which has little experience with guitar playing.

Thirteen episodes were broadcast on TBS between April 3 and June 26, 2009. The episodes began airing on subsequent networks at later dates which include BS-TBS, MBS, and CBC. The widescreen version aired on BS-TBS between April 25 and July 18, 2009. Seven BD/DVD compilation volumes were released by Pony Canyon between July 29, 2009, and January 20, 2010. An additional original video animation episode was released with the final BD/DVD volume on January 20, 2010. Both an English-subtitled and English-dubbed version by Red Angel Media began airing on March 16, 2010, on Animax Asia. At their industry panel at Anime Expo 2010, anime distributor Bandai Entertainment announced that they have acquired the first season of K-On! for a BD/DVD release.

Two pieces of theme music are used for the first season; one opening theme and one ending theme. The opening theme is "Cagayake! Girls" by the Sakura High Club (Yui Hirasawa (Aki Toyosaki) with Mio Akiyama (Yōko Hikasa), Ritsu Tainaka (Satomi Satō) and Tsumuki Kotobuki (Minako Kotobuki), along with Azusa Nanako (Ayana Taketatsu) starting in episode nine). The ending theme is "Don't Say Lazy" by the Sakura High Club (Akiyama (Hikasa) with Hirasawa (Toyosaki), Tainaka (Satō) and Kotobuki (Kotobuki)). From episode nine, the opening video features Azusa, and also features some minor changes to the music, particularly an additional guitar part during certain segments (alongside the initial two).

Ura-On!
A recap episode showing all the performances from the first season aired on July 25, 2009. A series of three-minute shorts entitled 'Ura-On!' were included on DVD and Blu-ray Disc volumes.