The fifteenth lord of Tosa Domain, his pen name was Yodo and he also styled himself 'Geikai Suiko' (the Drunken Marquis of the Whale Sea). One of the 'Four Wise Lords of the Bakumatsu' alongside Matsudaira Shungaku, Shimazu Nariakira, and Date Munenari, he backed Hitotsubashi Yoshinobu in the shogunal succession dispute and clashed with Tairo Ii Naosuke. In the Ansei Purge of 1858 he was placed under house arrest. As a moderate pro-shogunate advocate of opening Japan, he called for gentle shogunal reform through unity of court and shogunate. On the question of returning power to the emperor, he ordered the domain to submit to Tokugawa Yoshinobu the memorial drafted by Goto Shojiro and Sakamoto Ryoma, playing an important role in the realization of the Taisei Hokan in October 1867. However, when the shogunate was abolished by the Imperial Restoration Edict and Satsuma and Choshu seized the initiative, he wavered between factions out of sympathy for Yoshinobu. A lover of sake who styled himself the 'Drunken Marquis,' behind his bold personality lay a keen political sense. He died in 1872 at the age of forty-five. His contribution to the Taisei Hokan was indispensable to the peaceful realization of the Meiji Restoration.

A bold, sake-loving, free-spirited man. Though he wavered between loyalty to the shogunate and responding to the broad current of the times, he ultimately helped push through the historic decision of the Taisei Hokan. Politically pro-shogunate, he also possessed practical flexibility.

His contribution to realizing the Taisei Hokan gave him an important role at the turning point of modern Japanese history. He is remembered as an outstanding figure of the Bakumatsu era, inseparable from his colorful title 'the Drunken Marquis of the Whale Sea.'