Aoi is not Sana's cousin, despite the fact that Sana calls her mother his aunt. Her parents own the apartment building that Sana lives in. She prefers to be called Aoi-chan instead of Aoi-san, despite the fact that she is a year older than Sana. She wears glasses and has a busty physique. She loves to read books and is very energetic and clumsy. She has a very high-pitched voice and child-like character. Despite being childish, Aoi has a very caring personality, and never fails to aid a friend in need.