Koharu has a maroon hair with a pony tail, held by a cherry blossom clip, asparagus-green eyes and fair skin. She is normally seen with her school uniform which consists of a dress with collars with dark-blue and dandelion accents, black pair of socks and shoes with dark-blue and dandelion accents.
Her bag she carries is colored brown with gold accents and consists of pockets.
Koharu is a rather stoic and level-headed girl. She has expressed exasperation at Go's boastfulness and hyperactiveness.