Aegis is an android created by the Kirijo Group; she is the last surviving model of their experimental anti-Shadow weapon. In combat, she uses a wide variety of high-tech weapons, from machine guns and rocket launchers to long range guns and “rocket punches.” Aegis has the highest durability of any of the characters, and her Personas focus on physical attacks.
Aegis is introduced during SEES' summer beach vacation, where she is simultaneously the target of Mitsuru's retrieval mission and Junpei's "Operation Babe Hunt." She immediately shows an instinctual interest in protecting the Main Character which even she cannot explain. Ikutsuki has her assigned to aid SEES, and she enrolls in Gekkoukan High to act as the Main Character's bodyguard.
In the Persona 3: FES expansion, the player can access an epilogue to the main game called Episode Aegis (The Answer). There, Aegis replaces the Main Character as playable protagonist, inheriting his power to summon multiple Personas. The Main Character can also date Aegis in Persona 3: FES.