Hidan no Aria (Series)

Aria the Scarlet Ammo (緋弾のアリア) is a Japanese light novel series by Chūgaku Akamatsu with illustrations by Kobuichi. As of December 24, 2021, 36 volumes have been published by KADOKAWA 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 was announced, and began airing on April 15, 2011. The 10th anniversary special was published on March 25, 2019.

Plot
Tokyo Butei High school... It was a special school where armed detectives, also known as "Butei" are being brought up. Kinji Tohyama is a sophomore student who has the unique superhuman body which activates a "super mode" when it was stimulated by "something". He tries to conceal this fact to others in order to live a peaceful life. But trouble came to find him when he became a victim of a bombing incident, where he met the Butei High "Assault" department elite, Aria H. Kanzaki.