is a mixed-media project originally created by Humikane Shimada via a series of magazine illustration columns. It was later adapted into two light novel series, three manga series, an anime OVA, and a televised anime series. The story revolves around teenage girls who are essentially moe anthropomorphizations of military planes. The OVA preview episode was released on January 1, 2007. The televised anime series later premiered on July 3, 2008, concluding September 18. The second season began airing on July 8, 2010. A game adapted from the series for the Xbox 360 and the second game for the Nintendo DS will be released in 2010.