At the end of the 19th century when the social season was about to end, a series of murders occurred in London. The deceased victims were all prostitutes; their bodies were cut open, and their uterus deliberately removed. Due to the brutality inflicted on the victims, the police authorities and other prostitutes called the criminal Jack the Ripper.
Angelina Dalles is the true mastermind behind the attacks. Grelle Sutcliff, a Grim Reaper, joined her as a co-criminal after they witnessed her first murder. The prostitutes are all patients at the Royal London Hospital, where Angelina worked at. The order in which the victims died corresponded exactly to the patients on her abortion operation list.
Because of Jack the Ripper's disruption to the regular society, Queen Victoria had sent Ciel Phantomhive to investigate and discover his true identity. As noted by Ciel, Jack the Ripper's ways of killing were unconventional and unorthodox, and for this matter alone, it greatly distressed the Queen. The wounds were due to some kind of sharp tool that inflicts quick cuts, resulting in a painful death.
Undertaker had revealed that all the victims have had their wombs removed so accurately and professionally that the murderer had to be someone experienced in the medical field. In order to narrow down the suspects, Sebastian Michaelis had listed the conditions for being Jack the Ripper: a doctor who is knowledgeable about anatomy, has no alibi the day before the incident, and/or is connected with a secret society or black magic.
- Aleister Chamber
- Angelina Dalles
- Adam Heivitt
- Josiah Condor
- Nicholas Anthony
- Richard Oswal-
- Simon E-
- William Somerset
- Jack the Ripper relates to an actual, unidentified serial killer who attacked in London contemporaneously. He also murdered prostitutes by slitting their throat and mutilating the bodies. However, the historic Jack the Ripper did not always remove body parts and did not stick to just removing the womb.
- In Kuroshitsuji, Ciel never informs Queen Victoria or Scotland Yard about the true identity of Jack the Ripper, and in this way Yana Toboso stayed true to history.
- Angelina and Grelle became Jack the Ripper not long after the attack on Phantomhive Manor in December 1885. They killed prostitutes years before the real-life Whitechapel murders started in April 1888, or the first murder attested to Jack the Ripper occurred in August 1888.
- The major victims were based on the real victims of the actual Jack the Ripper. Mary Ann Nichols, Annie Chapman, and Mary Jane Kelly were based on their real-life counterparts.
- Mary Ann Nichols died in August 1888, about a week before Annie. Her real-life counterpart, however, died on August 31, aged 43. Interestingly, her corpse was found only 150 yards (approx. 137.16 cm) away from the Royal London Hospital, the workplace of the fictional Mary Ann's murderer Angelina Dalles.
- Annie Chapman died on the final day of the 1888 Season—presumably August 12. The real Annie died weeks later on September 8 at the age of 47. Like her real-life counterpart, Annie's corpse was found on the street.