Komanechi

Komanechi (or is it "Doctor" Komanechi) is the Sorceress/witch in residence at Dr. Kyoji's hospital, not much is known about her and how she managed to be there, however, her knowledge of magical potions and mixing them are top notch.

Komanechi has a pleasant disposition to Nanako and the others, however, she is the proverbial thorn in the side of Dr. Kuron as they are always arguing and trading insults, in one episode they almost traded blows. What amazes me is that inspite of the animosity between Komanechi and Kuron, they somehow live in the same residential quarters, next to each other in the hospital.