Mister Demi has shoulder-length white hair, with a pair of white pencils atop his head. Like most teachers, he has small black horns. His left bang resembles a keyboard. He accessorizes black glasses, and only his left eye is visible. He sports a white collared shirt, with black overalls over it. An eighth note is on the center of the shirt, and the left strap of the overalls have two white lines, accompanied by a large belt. His arms are black and white, whilst his hands are solid black.