Miki, Rintarou

Biografía

Miki is often flirty and smiles a lot. He doesn't seem to take most things too seriously, and he's often late with his paperwork (such as creating exams). When he's teaching, he's firm with his students. Miki enjoys drinking, and his personality turns aggressive when he's drunk. Miki can also be very cunning, even to the point of using people close to him to achieve his ends.

Miki bickers a lot with Hatanaka Izuna, and the two are close friends since their school years. He seems to enjoy causing trouble for others especially when he's with Hatanaka.

Miki is an action type youkai, which means a specific physical action gives him spirit energy to use his magic. In Miki's case, drinking alcohol invokes his powers. which makes him grow exponentially stronger. However, he gets drunk very easily (even from non-alcoholic drinks), so he usually loses control when activating his powers.

Up until he was old enough to drink alcohol, he was basically a human with a horn

(Source: Youkai Gakkou no Sensei Hajimemashita! Wiki)