Yes he is demon
A very stereotypical demon

He's pretty sweet, as well as smart, but what comes with smart and kind comes nerdy and dorky. (He's a dork. A big dork) he's not the best behaving and loves a bit of trouble. He can also come off as bashful and naive at first, later becoming more honest and "energetic". He can hide is demon features, but he chooses not to since he already goes to a school of misfits and other beings.