Black Butler (2014) on Netflix

Plot summary

Kiyohara Genpou is an orphan who presents herself to the world as a male earl, because the fortune of the Genpou family's Funtom Toy Company passes only to male heirs. In an unnamed Eastern metropolis she acts as one of the Queen's Watchdogs, and at her side is Sebastian Michaelis, a demon masquerading as her butler. She sold him her soul in exchange for revenge on those who massacred her family. Her household includes the clumsy maid Rin and the house steward Tanaka. Powerful citizens are being found desiccated, the latest the Queen's ambassador Anthony Campelle, and Kiyohara takes up the case. At the Eastern Ministry for State Security, an official warns the policeman Tokizawa that a Queen's Watchdog is a threat to the nation.