Aria the Scarlet Ammo Vol. 1 (novel)

Tokyo Butei High School--- A special school where armed detectives, also known as "Butei", receive education as well as training. Kinji Tohyama, a sophomore, has a unique body that can initiate an ability called "hysteria mode" when it is stimulated a certain way. He tries to keep it a secret but all his dreams of living the life of an Average Joe get shattered when he becomes a victim of a bombing incident and meets Butei High "Assault" department elite, Aria H. Kanzaki.