Hatto Gaki/Origin

Hatto-gaki is a group of texts of ancient laws compiled by Tokugawa Yoshimune in 1725 to constitute a code of laws useful to the shogunate. (Source: Japan Encyclopedia by Louis Frederic, Kathe Roth, Cambridge, Mass. : Belknap Press of Harvard University Press, 2002,  p. 298, ISBN: 0674007700 9780674007703).

In the days of the eighth shogun, Yoshimune, it being held that crimes were often due to ignorance of law, the feudatories and deputies were directed to make arrangements for conveying to the people under their jurisdiction some knowledge of the nature of the statutes; and the result was that the mayors (nanxishi) of provincial towns and villages had to read the laws once a month at a meeting of citizens or villagers convened for the purpose. Previously to this time, namely, in the days of the fourth shogun, Ietsugu, the office of recorder (tomeyaku) was instituted in the Hyojo-sho for the purpose of committing to writing all judgments given in lawsuits. But in the days of Yoshimune, the rules and regulations issued by the Bakufu from the time of Ieyasu downwards were found to have fallen into such confusion that the difficulty of following them was practically insuperable.Therefore, in 1742, Matsudaira Norimura, one of the roju, together with the three administrators, was commissioned to compile a body of laws, and the result was a fifteen volume book called the Hatto-gaki (Prohibitory Writings). The shogun himself evinced keen interest in this undertaking. He frequently consulted with the veteran officials of his court, and during a period of several years he revised "The Rules for Judicial Procedure." Associated with him in this work were Kada Arimaro, OgyQ Sorai, and the celebrated judge, Ooka Tadasuke, and not only the Ming laws of China, but also the ancient Japanese Daiho-ritsu were consulted. . ,This valuable legislation, which showed a great advance in the matter of leniency, except in the case of disloyal or unfilial conduct, was followed, in 1767, by reforms under the shogun, Ieharu, when all the laws and regulations placarded or otherwise promulgated since the days of Ieyasu were collected and collated to form a prefatory volume to the above-mentioned "Rules for Judicial Procedure," the two being thenceforth regarded as a single enactment under the title of Kajo-ruiten. "The Rules for Judicial Procedure" originally comprised 103 articles, but, in 1790, Matsudaira Sadanobu revised this code, reducing the number of articles to one hundred, and calling it Tokugawa Hyakkajo, or "One Hundred Laws and Regulations of the Tokugawa." This completed the legislative work of the Yedo Bakufu. But it must not be supposed that these laws were disclosed to the general public. They served simply for purposes of official reference. The Tokugawa in this respect strictly followed the Confucian maxim, "Make the people obey but do not make them know." (Source: A History of the Japanese People: From the Earliest Times to the End of the Meiji Era, Frank Brinkley, Dairoku Kikuchi,Encyclopaedia britannica Company, 1915 - Japan, ch. 42: Organization, Central and Local; Currency and the Laws of the Tokugawa Bakafu, p. 641-642, OCLC Number:413099).