In the "Black Butler" saga, the human protagonist is a boy named Ciel Phantomhive. This film introduces a new protagonist, a girl named Shiori Genpo/Kiyoharu Phantom.
The "Black Butler" story was originally set in the 19th century, in the ruling era of Queen Victoria. This film is set in the year 2020 to allow for a more reasonable mingling of Asian-European cultures.