Generally commerce in tokugawa japan was conducted by oral agreements on the basis of mutual trust and confidence between the parties. because of the trust factor, neither buyer nor seller dared default on an oral contract. if he did, when word got out into the market place, the breaching party would be ostracized.
In summary, tokugawa law consisted of codes,sumptuary and customary laws continued by the tokugawa shogunate during the edo period. sankinkotai, the alternative attendance system, undoubtedly had the singularly greatest impact on the political economy and the development of a centralized feudal mercantile system.
Other aspects of tokugawa law are interrelated and interacted with the sankin kotai system and each to from a body of tokugawa law relating to matters of trade and commerce and provided a basis for the merchants of trade and provided a basis for the merchants of tokugawa japan to rise in wealth and economic success and prepare japan itself for economic success in the nineteenth century and there after.
Merchants and artisans/craftsmen, although ostensibly in a lower class than peasant-farmers in the hierarchy of the class society of tokugawa japan, actually had the upper-hand in matters of trade, and commerce, and wealth, especially in dealing with the samurai class, who disdained anything connected with trade or commerce. Although characterized by many historians as the dregs of tokugawa society, the merchants, as became most evident in the twentieth century, proved to be the key to japan's dynamic performance in the international marketplace. Akio Morita of Sony recognized in the 1950s that most japanese companies doing business in the United States relied on the experienced japanese trading companies.
The major aspects of tokugawa law which were most predominant in their impact on providing the merchant with foundations for economic wealth, power and dominance during the Edo Period were:
1.buke shohatto, which institutionalized sankin kotai the alternative attendance system
2.kokudaka, the land tax system and
3.samurai fixed rice stipends.
Other important elements in the legal structure included: disenfeoffment of samurai land, adoption of the culvitor (nago) system and relocation of the samurai into the castletowns and Edo and abolition of control point (border guards).
All of the above, together with their interrelating impact upon and interaction with non-legal factors, such as urbanization, agricultural growth, and population control, are also important factors.
In addition there were two other significant historical developments concerning tokugawa law which require consideration: "The Three Great Reforms" and "The Tanuma Era".
The great promulgators of tokugawa law were leyasu, Hidetada and Iemitsu (the first, second and third Shoguns-father, son, and grandson), among whom Ieyasu was undoubtedly the stongest during the founding of the of the tokugawa shogunate. Next in legislative distinction was Iemitsu because of his foreing seclusion and anti-Christian edictsbof 1635.
The most active period of legislation, however,occurred during the term of the eighth Shogun,Yoshimune (1716-1745).
Ironically, the other two most prominent Legislation of tokugawa japan were not shoguns, but served in the capacity of senior councilor of regents to minor or mentally incompetent shoguns.