Shirasu Azusa (白洲アズサ, Shirasu Azusa) is one of the students studying in Trinity General School who wields an Assault Rifle.

An ice queen who belongs to Trinity's Supplementary Lesson Department.

Originally, she had dropped out of her school, but for one reason or another, she has returned to school and is working on her schoolwork again. She is lonely, but she voluntarily keeps her distance for fear of bothering others and is worried by the students in Supplementary Lesson Department.