Otomo Hirofumi was an Imperial courtier. He served as the attendant and protege of Otomo Banu, whom Banu had known since Hirofumi was a child. At some point around the time of the War Against the Shadow Hirofumi joined the Cult of Ruhmal. He desired to kill Banu, who was working against the cult, so that he could take Banu's position and further the cult's aims. Hirofumi was exposed after attempting to frame Banu as a cultist at a party.