Myoga means a kind of tax in the Edo period that was paid to the Edo bakufu or domains in consideration for the use of mountains/fields/rivers/seas or to grant a business license
Since it was usually paid in cash, it was also called Myogakin/Myogaei (ei means Eiraku-tsuho (bronze coins)).
Originally, the term Myoga was a synonym for myori, which means divine protection. Money and goods that were offered to temples/shrines as gratuity for a Myoga prayer or receiving Myoga also came to be known as "Myoga." Later, feudal lords claimed to be the protectors of the people of the domain and stressed the benefit of the existence of such protectors (kokuon (benefit given by the lord of domain)). With the above pretext, feudal lords imposed Myoga, which corresponded to nengu (land tax) imposed on farmers, on merchants and traders who were not required to pay nengu. Further, they imposed Myoga on people who gained profit from business that required a license from the domain, such as mine workers, as well as people who gained profit from mountains/fields/rivers/seas that were under the rule of the lords, such as whale fishermen. In a sense, the above was modeled after the relation between lords and farmers under which farmers worked at farmlands (cultivation) that were under the rule of lords and pay nengu while being protected by the lords.
A similar tax called Unjo also existed. Unjo was also imposed on merchants and traders, and there are following views on the differences between the two taxes. "While the amount of Unjo was fixed, no fixed amount existed for Myoga." "While Unjo was paid by tax payers according to the order of lords, Myoga was paid voluntarily in the form of an offering for kokuon, Myoga given by the lords (however, it is another matter whether it was really paid voluntarily)." "While Komononari (miscellaneous tax) and Unjo existed since the early stage of shogunate system, Myoga was newly imposed later when kabunakama (merchant guild) was established. In view of the fact that there were cases where a fixed amount was set for Myoga, the reality might be similar to the description of "Jikata hanreiroku" saying "Unjo and Myogaei are the same, (snip) you may use them interchangeably."
The most well known example of Myoga was the one that was imposed by lords in for the exclusive business right of kabunakama. While the amount of Myoga was big for the first year of permission (shonenkin/shonengin (down payment)), a small amount of Myoga was imposed annually (nennenkin/nennengin (annual payment)). Myoga was paid either in gold coin, silver coin or both if necessary, and the members of kabunakama jointly bore the cost. Myoga was abolished when kabunakama was once abolished in the process of Tenpo Reform. Though kabunakama was revived later, Myoga was no longer imposed on kabunakama.
Other than kabunakama, there were cases where Myoga was imposed on people who constructed houses in an open space inside town or those who used river banks for docking space.
Myoga was abolished based on "Shoho taii" (a kind of commercial code) enacted in the process of the Meiji Restoration, but some of them were later revived as Unjo or modern trade tax.