In life, Zenjubou was a sniper who attempted to assassinate Oda Nobunaga. While on the run as a fugitive after his failure, he met the sorcerer Kashin Koji, who disguised his appearance by turning him into a woman. They still use the masculine pronoun Ore as a servant.
Unlike most of Fate characters from the Sengoku period, they're from proper human history as opposed to the alternate history of the Koha-Ace timeline, and as such isn't familiar with the female Nobunaga.
