The most famous entrepreneur in the early Tokugawa Era (the early seventeenth century) was Yodoya Tsuneyasu. Yodoya came to Osaka, then the capital of the government ruled by Toyotomi Hideyoshi. Yodoya made money as a building contractor for the Toyotomi government and then for Tokugawa Ieyasu, who overturned the rule of Hideyori, Hideyoshi's son. Yodoya and his descendants then made a prosperous business as traders of rice, vegetables, fish, and so forth. They prospered and lived so extravagantly that the irritated Tokugawa government ordered Yodoya's business to be closed in 1705 and confiscated all the wealth.
Yodoya made a fortune during the civil war by working for the lords who were fighting with each other. It was more or less a transitional period and Yodoya could accumulate wealth by making full use of his contacts with the lords and making a clever judgement as to who would win the civil war.
By contrast, most enterprises in later periods prospered from commercial demand. The biggest three were Konoike who started with brewing sake (Japanese rice wine), Sumitomo who started with copper refining and selling medicine, and Mitsui who started as a draper. They were all innovators in their businesses. Konoike succeeded in transporting sake from the sake-brewing centre near Osaka to a growing market in Edo ( Tokyo), thereby enlarging the market tremendously. Sumitomo and their collaborator, Soga Riemon, started copper-refining with the technology they learned from a European merchant. They also pioneered the exporting of copper. Mitsui's innovation in retailing included