Aoi has deep blue eyes that fade to a lighter shade at the bottom, white pupils, and straight black hair styled in twintails. She wears two blue butterfly clips to keep her hair in place and dons the standard Demon Slayer uniform with a white nurse dress layered over it. Aoi is known for her tough and firm demeanor often seen with a frown. Despite her strict exterior, Aoi harbors kindness and care within her. She also possesses medical knowledge and aids in taking care of injured slayers.