The manga that I am looking for would have been up before 2014. It was a Demon school manga. The main character was a guy who was supposedly human but for all I know he could have come out as something else later on. He was not the most confident person. One if his friends is a demon girl who slept with a teacher. Its been so long that is honestly all I can remember. The art style was really good though.

Remake thread without a useless poll

A just ruler amongst tyrants