He advocated the Kogi Seitairon (political theory focused on the parliamentary system), of which the Edo bakufu (Japanese feudal government headed by a shogun) was a central faction, as Tosa clan's public opinion and made Satsudo Meiyaku (the alliance between Satsuma and Tosa) in order to realize Taisei Hokan (transfer of power back to the Emperor).
江戸幕府を中心とする公議政体論を藩論とし、大政奉還の実現に向けて薩摩藩との間に薩土盟約を締結する。