Aria The Scarlet Ammo (緋弾のアリア Hidan no Aria) is a Japanese light novel series written by Chūgaku Akamatsu and illustrated by Kobuichi. As of March 2012, 16 volumes have been published by Media Factory under their MF Bunko J label. A manga adaptation by Yoshino Koyoka started serialization in the seinen manga magazine Monthly Comic Alive on September 26, 2009.An anime adaptation began airing on April 14, 2011 and concluded on June 30, 2011. An OVA was released on December 21, 2011. On 12 December 2013, it was teased that a new Aria the Scarlet Ammo Project is in the works; more information will be revealed with the release of 16th volume of the novel. As of July 2014, a new Aria the Scarlet Ammo project was teased with a video.
Kinji Tōyama is a student at Tokyo Butei High, a universal educational facility. At this school, students with an aptitude for the work undertake special training in order to learn the path of the Butei - a national qualification permitting its holders to possess various weapons and capture criminals. The Butei were established to counter worsening crime conditions around the world, with training in various specialized fields. Shortly after Kinji decides to quit the Academy due to personal reasons, he is attacked by the Butei Killer, a criminal notorious for eliminating Butei - a case of the hunters becoming the hunted. The elite Butei Assault prodigy Aria H. Kanzaki comes to his rescue and from that moment on, Kinji's future as a Butei changes drastically.