Obanai Iguro was the chemistry teacher at Kimetsu Academy. He was a strict teacher and hated rule breakers.

He always had his pet snake, Kaburamaru, around his neck during class. During tests Kaburamaru would slither around the class looking for any cheaters.

He wouldn’t allow any student to fail in his class. If a student failed his test then they would be tied to a post and get shot with bottle rockets. Surprisingly the school allowed that.