Aria the Scarlet Ammo AA IV is the fourth and possible final volume of the Hidan no Aria AA novel series released on December 25, 2015.
- The light novel was released two days after the Hidan no Aria AA anime series final episode aired.
- The light novel series was possibly completed within one year.
- Former IU members turned Butei High students Riko Mine, Jeanne d'Arc, and Kyouchikytou appear.
- Other surviving members of the Mamiya Family appear.