Though she has the form of a young human girl, she's actually a fox youkai who's roughly 330 years old. Normally she wears common miko clothing (from serving the Kagurazaki miko family for generations) along with her yellowish blonde hair and red eyes. She is prone to entering "half-demon form," however, by popping her tail(s), claws, and ears whenever emotional or agitated.
Often seen with Tamaryu and later Ran, having her crush on the former expand into outright polygynous engagement with the whole love triangle.
After being tapped by the Kuuko Sachi to be a successor in the "Holy Trio" (as "Radiant Heaven Mikoko") of youkai along with Tamaryu and Ran, she finally stopped lazing about in her studies, and learned how to use her fox youkai illusion magic transform into an adult.
In her adult form, she has long, straight black hair and keeps her red eyes while still usually wearing her miko outfit. She also develops a bust that Tamaryu sometimes violently envies.
Shizuki uses her adult form to signify her occupying her role as a teacher, and changes back to a child as soon as she's doing anything for personal reasons.
