After the victory, he and Hirobumi ITO signed the Treaty of Shimonoseki as delegates in 1895, and put an end to the war under the conditions which were advantageous to Japan.
戦勝後は伊藤博文とともに全権として明治28年（1895年）、下関条約を調印し、戦争を日本にとって有利な条件で終結させた。