It is unclear if anyone in the manor is aware of Sebastian's demonic powers/persona besides Ciel, but that hardly seems to matter. Handling the manor are Ciel's ever-faithful employees: Finnian, the youthful gardener with incredible hidden strength Mey-Rin, the near-sighted maid who keeps a handy arsenal hidden away Bardroy, the incompetent American cook who can find more than one chemical use for flour and Tanaka, the steward.

Now bound as Master and Butler, Ciel and Sebastian return Phantomhive manor to it's glory in service to the Crown, drawn to investigate strange happenings, murders, and intrigues at the behest of Her Majesty, Queen Victoria. Drawn to Ciel's side by his cries for vengeance, Sebastian forges a contract with the young Phantomhive heir: obedience and servitude to discover the faces of the murderers in exchange for Ciel's soul. Ciel is the remaining heir to the Phantomhive manor, determined to uncover the truth behind the death of his parents. Sebastian Michaelis is a demon of the highest order with almost unlimited power and style.

Black butler season 2 episode 1 sub