Ouka is teenage girl with an extremely well endowed figure and in terms of beauty is described as "perfect" by Kanade Amakusa and other boys at her school. Ouka has long, dark-brown hair that flows down her back and passes her hips and has a pair of round light purple eyes. She wears a pink headband with a big bow on the left side of her head. She has been seen in two outfits; the standard girl's uniform, and a long-sleeved purple sweater with pink colored skirt. When she wears the Academy's uniform, she unbutton the bottom part of her shirt, revealing a bit of her stomach also wears a pair of brown boots.
She is a cheerful, hyperactive, airheaded and sometimes a happy-go-lucky girl. However, despite that, she is also very shy as shown when exposing her underwear to certain people makes her embarrassed. She also recalled her mother's words of only crying in front of the man she loved.
She shows that she really has a girly side as she got scared at amusement park ride and was touched when Kanade carried her.
She has a tendency to refer people with cute nicknames like Kanade as "Amacchi" and Furano as "Furanocchi". It is revealed that she is best friends with Konagi, a girl who is placed as the third in the popularity rankings, and they continue to be on good terms despite Ouka being in the Reject Five herself.