Natsu Fest Kyoku 1 "Rule" (Ep. 12 'Natsu Fest!')

Natsu Fest Kyoku 1 "Rule" (#12 'Natsu Fest!') or Summer Festival Track 1 "Rule" (#12 'Summer Festival!') is an "Insert Song" of the band BCS, produced by Pony Canyon and published on the 22th of December 2010 within the album K-ON!! Official Band Yarouyo!! ~Let's MUSIC!! 3~.

The song was written by Hotaru and composed by Tom-H@ck.

Appearances
As an insert song, "Natsu Fest Kyoku 1 "Rule" (#12 'Natsu Fest!')" has made one or more appearances during the K-ON! anime:
 * In season 2, episode 12 during BCS' performance at the Summer Festival.