In Victorian-era London, on the night of Ciel Phantomhive's tenth birthday a fire destroyed his manor and killed both of his parents. In a moment of death Ceil strikes a deal with a demon, his soul in exchange for revenge. This demon becomes his butler and calls himself by name of Sebastian Michaelis, to protect and serve Ciel until the deal has been completed. One month after the fire Ciel returns from being missing, with his new butler Sebastian. Ceil is now the head of the Phantomhive corporation, handling all business affairs as well as the work as the Queen of England’s guard dog and looking for his parents murders.
In Tokyo, an impenetrable field known as "Hell's Gate" appeared ten years ago. At the same time, psychics who wield paranormal powers at the cost of their conscience also emerged. Hei is one of the most powerful of these psychic agents, and along with his blind associate, Yin, works for one of the many rival agencies vying to unlock the mysteries of Hell's Gate.
Five girls live in 19th century London, a city within the Albion Kingdom divided into east and west by a large wall. The girls serve as undercover spies enrolled as students at the prestigious Queen's Mayfair school. The girls make use of their individual abilities to remain active in the underground world of disguise, espionage, infiltration, and car chases.