The premier metalworker of his day, Natsuo was also a painter and calligrapher and a student of classical poetry. He began as an adopted apprentice to the swordsmith Kano Chisuke, eventually setting up his own premises in Kyoto in 1846. He moved his business to Tokyo in 1854, where he enjoyed increasing success and acclaim, winning the top prizes for metalwork in National Industrial Expositions. Joining the Tokyo School of Art in 1889 as the first professor of metalwork, Natsuo and his many students were proponents of sculptural metalwork, the wearing of swords having been revoked in 1876. Natsuo was appointed Artist to the Imperial Household (Teishitsu gigeiin) in 1890.
Giovanni Morosini was one of the great collectors of Arms and Armor and a major donor to the Metropolitan Museum of Art.