Hakari-za is za (trade guild) which imposed a monopoly on manufacturing, distribution, test and repair of scales with the special license of the Edo bakufu during the Edo period.
Hakari-za originated in the Muromachi period, and according to 'Sankazue' (Picture Collection of Three Coins: History of Coinage in Japan), saying that 'The Zin family came from Sei-shu (Ise Province), served in Kyo-Muromachi, got a license of hakari-za and lived in the capital since then,' hakari-za was controlled by the Zin family.
During the Tenbun era, another hakari-za was created in Kofu and controlled by Shuzui YOSHIKAWA. It is said that precise scales were required in Kai Province, where gold was produced. The descendants of Shuzui YOSHIKAWA use a family name Shuzui.
When Ieyasu TOKUGAWA entered Edo during the Tensho era, Heizaburo SHUZUI of Kofu went to Edo and asked Ieyasu for the right to control the Kenko (leather scale) business in Kanhasshu (the Eight Provinces of Kanto region), explaining the old relations from Kofu. According to 'Mikawa Go Fudoki' (The Topographical Records of Mikawa Province), Ieyasu praised him and handed goshuin (letter bearing the shogun's scarlet seal) to him, granting him a license.
While in Kyoto, Zenshiro Zin, a descendant of the Zin family, got a license from Ieyasu TOKUGAWA during the Keicho era and had maintained hakari-za since then, Shoo-ninenrei (official document issued in the second year of Shoo era) was issued by Ietsuna TOKUGAWA, dividing Japan into two as in the case of masu, and allowing the Shuzui family to control scales in 33 provinces in eastern Japan and the Zin family in Kyoto to control scales in 33 provinces in western Japan.
In the third year of Manji era, however, the Zin family of Kyo-hakari-za fought against the Shuzui family of Edo-hakari-za. As a result of the decision made by the bakufu, the Zin family was deprived of the right to control the scale business in 33 provinces in western Japan, and the Shuzui family began to control the scale business all over Japan.
Hakari-za not only sold tested scales but also had a license to test old traditional scales. Scales which did not pass the test were confiscated and those which were good enough were guaranteed with a stamp of Shuzui. Hakari-za was allowed to collect money of ichibu per scale as the cost of the stamp, but later the test of old scale was abolished and it was prohibited to hide old scales or to use inaccurate scales. It was stipulated that people should use new scales produced by hakari-za, and when a scale was damaged it should not be repaired by its owner but should be sent to hakari-za for repair. Thus hakari-za and the Shuzui family made enormous profits.
As hakari-za had to visit various places to test scales for the purpose of controlling the scale business all over Japan, Shuzui's influences extended even to tenryo (a shogunal demesne). However, because it was not easy to test scales within lords' territories, the Edo bakufu tried to protect hakari-za by granting officers of hakari-za the privilege to impress tenma (post horse).
Later, hakari-za established branches or sub-branches in various places. In places where hakari-za could not send its officer, it designated local residents as its officers. Hakari-za had local lords maintain such branches by paying them myogakin (money to dedicate). That is why Shuzui scales spread all over Japan and scales were integrated in Japan. After the Meiji Restoration, in August in the eighth year of Meiji era, Weights and Measures Control Law was issued and hakari-za was abolished in February in the ninth year of Meiji.
After the Meiji period, the Shuzui family sold scales and is now continuing business as an industrial measuring instrument manufacturer, Shuzui scales co., LTD.