Born to a family of Dutch scholars and physicians in Ako District, Harima Province, he studied at Ogata Koan's Tekijuku in Osaka before going to Edo to study military science. As commander of the shogunate's Western-style infantry (Denshu-tai) he fought in the Boshin War, distinguishing himself at the Battle of Utsunomiya Castle. In the Battle of Hakodate he holed up with Enomoto Takeaki at Goryokaku and resisted to the last. After surrendering he was imprisoned but eventually pardoned and entered Meiji government service. As minister to Korea (1893-94) he was on the front line of Japan's diplomatic and military actions on the peninsula, facing the Donghak Peasant Revolution and the outbreak of the Sino-Japanese War. After returning home he served as president of the Peers School and as a member of the House of Peers. He died on June 15, 1911, at seventy-seven.

A practical man who combined knowledge with the capacity for action. He possessed wide-ranging abilities spanning Dutch learning, military science, and diplomacy, adapting to changing times while pursuing his mission.

A career with two faces—Bakumatsu resistance and Meiji contribution—symbolizes Japan's transition from the Bakumatsu to the Meiji era. His activities as minister to Korea were deeply connected to the road to the Sino-Japanese War.