Blue Exorcist

A boy with glasses sits at a desk in a classroom as a white, spiky creature appears before him, then the scene cuts to the boy being flung through the air with a black tail-like appendage, followed by a close-up of a large green-eyed creature's face, then the boy with the creature's head now red and steaming, then a close-up of the boy's determined face, and finally the boy and a pink-haired boy facing off in a tense confrontation while a blonde girl and a bespectacled boy watch.