Youko has long green hair and orange eyes. As a vampire, she also possesses long canine teeth and wings. Although she is able to hide her wings, Youko is unable to do so with her canines which leads to her avoiding showing her teeth while at school as much as possible. She has a very shapely physique, and is mostly seen in the high school uniform, comprising of a light blue blazer, white blouse, a mauve and blue striped tie, along with a matching skirt, black tights and red Mary Janes.