Ryoma laid down together with Shojiro GOTO Eight Rules Laid down on a Ship, Shojiro GOTO persuaded Yodo YAMAUCHI, and they realized Taisei-hokan (the Restoration of the Imperial Rule), which was a proposal from Tosa clan.
後藤象二郎とともに船中八策を策定し、後藤象二郎が山内容堂を説いて土佐藩の進言による大政奉還を実現させた。