Mikotoba Yuujin

Yujin shared a flat with London's soon-to-be legendary detective, Herlock Sholmes, eventually becoming his investigative partner.

When the secret trial for the Professor was held, Mikotoba took part in the autopsy of Klint van Zieks as first assistant and was responsible for writing the autopsy report. Though Mikotoba had qualms about the findings of the autopsy, he wrote down John Wilson's findings dutifully - such as the discovery of Genshin Asogi's ring in the stomach of Klint van Zieks by Wilson. The findings in this autopsy were later used to convict Genshin Asogi as the Professor.

Nine months after John Wilson's death, Mikotoba received a letter from Sholmes about the "Case of the Haunted Lodging", describing how at the end of the case the bloodied dog collar worn by Klint van Zieks' bloodhound Balmung was found in a thief's stash. Mikotoba also read the reports penned by returning student Soseki Natsume of his times in Great Britain, which also covered the case. This prompted Mikotoba to visit Natsume and directly speak to him about what he had seen. Remembering that Susato saw the box containing the manuscript of the Hound of Baskerville, Iris' unpublished novel which almost completely described the truth behind the Professor Killings, Mikotoba grew worried that his daughter would uncover the truth before it was ready to come out. In order to postpone the discovery of the truth, Mikotoba sent a telegram to Susato, which claimed that he had suddenly fallen ill with a grave illness and needed Susato to immediately return to Japan.