Aoi is a young girl of average height, with deep blue eyes that fade to a lighter blue at the bottom,along with white rectangular pupils,straight black hair with a parted fringe and twin-tails.She wears two blue butterfly clips to keep her twin-tails in place.She wears the standard Demon Slayer uniform with the addition of a white nurse dress on top of it,with a blue sash around her waist.Her uniform is tinted slightly blue.

Obanai is the Serpent Hashira who has a pet snake called Kaburamaru.