He studied at the domain school Kodokan, and promoted reform of the domain administration. During the Boshin War he was a leader in the Saga forces committed to the overthrow of the Tokugawa shogunate.
Takata Oki worked for the cause of the Meiji Restoration (1868). He was appointed a Court official (1868) and directed the removal of the capital from Kyoto to Tokyo, together with Shimpei Eto, also a former Saga Clan retainer. Takata Oki was appointed Governor of Tokyo, Minister of Civil Affairs (1871), Education Minister, Court Councilor and Justice Minister. He was made a Count for his efforts in legislation (1884). Was appointed Chairman of the Senate (1885) and later President of the Privy Council (1889).