Doctor Yogami was a Japanese botanist who approached Dr. Wilfred Glendon during the charity ball being held at Glendon Manor, Dr. Yogami claimed to have met Dr. Glendon while in Tibet; "Only for a moment. In the dark." In truth, Yogami had met Glendon, because he was the werewolf who had bitten his English counterpart on the arm. Like Glendon, Yogami's purpose in Tibet was to acquire a specimen of the mariphasa plant, but only so he could use its anti-lycanthrope powers to quell his bouts of werewolfism.
Because Glendon managed to acquire the mariphasa in spite of his injuries and whisk the specimen back to his laboratory in London, London was where Yogami went after leaving Tibet. He tried twice to persuade Glendon to give him two of the blossums from the mariphasa, first at the party and later when Glendon caught him snooping about in the conservatory. Glendon turned him down both times, refusing to believe the Japanese botanist's stories about the mariphasa being an antidote for lycanthropy.
Undaunted, Yogami snuck into Glendon's lab on the first eve of the full moon and stole the only two mariphasa blossums which had bloomed under the artificial light of Glendon's moon lamp. These he took back to his apartment, and as a result, when Glendon became stricken by his lycanthropy that night there was no antidote at hand. He fully transformed into a werewolf and began to terrorize London.
The two blossums which he'd stolen did not last, and Yogami had his own bout of werewolfism, attacking and killing his housekeeper, Millie. Desperate, he made his way to Glendon Manor and broke into Glendon's lab just as his rival werewolf was returning, fresh from a fruitless attack on his own wife, Lisa Glendon. When Glendon's back was turned, Yogami grabbed the final mariphasa blossum and used it on himself, curing his lycanthropy for that night. Without the remedy of the mariphasa, Glendon transformed into a werewolf as he and Yogami grappled. Yogami was no match for the fierce beast, and Glendon choked him to death.