In the world of Hidan no Aria AA, there are special students called Butei who are authorized to carry weapons, investigate crimes and solve various incidents. One of the best of these students is an S-rank second year at Tokyo Butei High School named Aria Kanzaki. On the opposite end of the scale is E-rank first year named Akari Mamiya.

• Ayane Sakura
• Ayaka Imamura
• Mai Nakahara
• Rie Kugimiya
• Mao Ichimichi
• Yui Horie
• Chinami Hashimoto
• Momo Asakura