Kyouichirou Mikage

He is a science teacher at the same school where Honoka and Kagari were studying, he is also a wizard who came from a family of witches and wizards, and he is affiliated with the workshop witches. He specialize in potions and manipulation of dimensional rifts. Though he doesn't hold any contract with the city of Tougetsu, he, however is the one who is in charge of erasing or altering the memories of the residences of Tougetsu City about the witches existence.

He is Natsume's uncle.

(Source: Wikipedia)