Abandoning his traditional family business, Ōkura became a weapons dealer in the turbulent period preceding the Meiji Restoration, the 1868 coup d'etat that overthrew the feudal Tokugawa regime in Japan. He then formed the Ōkura Company, which became one of the first businesses to engage in foreign trade. Under Ōkura's leadership the company later branched out into mining and industrial enterprises. In his later years Ōkura, who had extended his enterprises to the mainland, became a philanthropist and a promoter of Sino-Japanese friendship.