Tosa official. Negotiator and supporter of an alliance between Choshu and Satsuma despite the distrust between the two clans and their leaders: Saigo and Kida. Helped Choshu in the war against the Bakufu. Assassinated in December 1867 as he was taking preliminary steps toward the organization of the new regime.
He appears in the flashback scene in the Rurouni Kenshin movie, Ishinshishi no Requiem. His name is mentioned in the Japanese version. Kenshin was bodyguard to Katsura (Kida) during the meeting between the Satsuma and Choshu clans that Sakamoto was presiding over.