Mary is a girl of average height with long blonde hair styled into two ponytails that are tied with black ribbons, and dark-yellow eyes.

She wears the standard Hyakkaou Private Academy school uniform. A red blazer with black trim around the cuffs and collar and gold buttons. Beneath the red blazer, she wears a white button-up shirt and black tie. She wears a gray pleated skirt, black-colored stockings and regular brown loafers with black soles.