Obanai is a chemistry teacher at Kimetsu Academy. Obanai is a very harsh and strict individual who shows no concern for those who do not abide the school conduct. He does, however, have a soft spot for those he loves. He has a pet snake named Kaburamaru, who is always wrapped around his neck. If his students fail his tests, he shoots at them with bottle rockets. He always wears a face mask. He has two scars on the side of his mouth. He has heterochromia, one eye gold and the other teal.