Ciel is a typical 17 year old boy, in high school. Until a new teacher comes in to teach and changes his whole world, only to tell Ciel many secrets and take him into his own world.
Sebastian is a 23 year old teacher at Kuroshitsuji high school, who takes interest into one of his students, soon to find out Ciel had been his old lover. But since he lost his memories when he was young he forgot Sebastian. How could he make him remember what they had?