He first distinguished himself as a bright scholar at the Shoheiko (Shogunate college) and was appointed professor at the Kitenkan school at Kofu, Yamanashi Prefecture. Being closely associated with Yukichi Fukuzawa and others he became acquainted with foreign affairs and entered politics. In 1864 he accompanied Chohatsu Ikeda, Lord of Chikugo, to Europe.
After the Meiji Restoration (1868), he served with the Foreign Office. In 1871, he accompanied Ambassador Tomomi Iwakura to Europe and America as chief secretary. He was once an acting minister to China ana a member of the Diet.
Late in life he was selected a member to the committee for historical research on the Meiji Restoration. He also wrote some books on diplomacy and a history of the closing years of the Tokugawa regime.