20 sen coin

Twenty sen coins were first struck towards the end of 1870 (year 3 of Meiji) from a newly established mint at Osaka.[4][5] This was initially done by engineers from the United Kingdom, as Japan did not have the technology or raw materials to manufacture new coins.[6][7] The coins made during this time were not officially released for circulation until the following year (1871) after a new currency act was promulgated.[8] Twenty sen coins along with twelve other denominations were adopted by the Meiji government in an act signed on June 27, 1871.[9][10] This new coinage gave Japan a western style decimal system based on units of yen, which were broken down into subsidiary currency of sen, and rin.[11][12] Twenty sen coins dated 1870 (year 3) were initially authorized to be struck in .800 silver, weighs 72.2 grains (4.68g), and has a 23.62mm diameter (0.93 in).[13][14][lower-alpha 1] The first design used is called rising sun dragon (旭日竜, Asahi Ryu), which had its features engraved by a commission of Japanese artists.[6] This design features a dragon with an open mouth on the obverse, while the reverse has a paulownia decoration with a sunburst in the center with the chrysanthemum seal up on top. Twenty sen coins were initially legal tender only up to the amount of 10 yen which was fixed by government regulations.[17] The amount of silver in the coin soon became an issue as their weight per face value became lighter than the silver 1 yen coin. An amendment to the new currency act (Daijo-kan Declaration No. 341 (新貨幣量目寸法改正)) was adopted in November 1872 (year 5) which intended to increase the weight of the twenty sen coin. This action was never carried out as the new currency act was amended again towards the beginning of the next year.[8] Changes to the weight, size, and design of the coins were implemented in February 1873 (year 6) by Daijo-kan Declaration No. 46.[18] The weight issue was resolved by adjusting the coin from 72.2 to 83.2 grains (5.4g), this step was done to avoid any public mistrust on the silver content.[13][14][19] Twenty sen coins were also reduced slightly in size from 24mm to 22.42mm.[18] The second design is called dragon silver 20 sen (竜二十銭銀貨) as the sunburst on the reverse was replaced by a wreath. Latin script is used for the first time with "20 SEN" on the obverse under the dragon, and the medallic orientation was flipped.[18][20]

It is recorded by Edward Reed that production of twenty sen coins continued until at least June 30, 1878.[21][22] These coins were last dated 1877 (year 10), and could have been impacted from the Satsuma Rebellion.[18] Only proof strikes were made for coins dated 1880 (year 13) for exclusive use in presentation sets.[23] During the next few years, Japan experienced a sharp drop in prices and contraction of the economy in response to high inflation caused by the Satsuma Rebellion.[24] Large amounts of devalued inconvertible notes were in circulation from the aftermath of the rebellion. The Bank of Japan was established in 1882 (year 15) to remedy the situation, and two years later convertible banknotes were issued.[24] An imperial ordinance was issued in June 1885 stating that silver payments would be resumed after January 1, 1886.[24][25] For reasons unknown there are no twenty sen coins dated 1889 or 1890 (year 22 and 23), during this time a special fund was created for the redemption in silver for all government notes.[25] The Japanese government promulgated the "currency law" (Meiji 30 Law No. 16) in 1897 which replaced the previous "new currency act". This law abolished the silver yen at which subsidiary silver coins were previously fixed at, and officially switched Japan from a silver standard to a gold standard. No changes were made to twenty sen coins as they were re-established to their previous weight, size, and design.[26]

Production continued as the price of silver bullion remained steady throughout the rest of the century. This changed when silver bullion began to rise sharply in 1903 (year 36) which threatened to exceed the face value of the twenty sen coin.[18][27] An amendment to the "currency law" was promulgated in March 1906 which lowered their size from 22.42mm to 20.3mm, and their weight from 5.4g to 4.1 grams.[27][28] The third and final design used on these smaller coins is called rising sun 20 sen (旭日20銭銀貨, Asahi Nijusen) as a sunburst design on the reverse was restored.[27] The wreath design previously used on the back side of the dragon coins was adopted for the obverse. Twenty sen coins were produced afterwards until 1911 (year 44), concluding the circulating portion of the series.

Emperor Taishō was enthroned in 1912 following the death of Emperor Meiji. Coinage in general was impacted by World War I which broke out two years later, bringing Japan a booming economy due to a large trade surplus.[29] The negative effects from this event included an increased demand for subsidiary coins which led to a coin shortage.[30][31] Silver bullion was in high demand causing prices to rise above the face value of the twenty sen coin.[27] The Japanese government responded by taking measures to temporary ban the export of silver. These efforts were ultimately unsuccessful which led to the issuance of 20 sen emergency banknotes in November 1917.[27][29] As the price of silver rose, the issue of coinage was also addressed for twenty and fifty sen coins. The "currency law" was revised in May 1918 (Law No. 42) to lower the silver content in twenty sen coins to 72% silver and 28% copper.[32] Other changes included a reduction in size from 20.3mm to 16.7mm, and in weight from 4.1 to 3 grams.[33] The coins struck from 1918 to 1921 are known as Yatagarasu sen (八咫烏銭, eight-span crow sen) after the design featured on them.[33][lower-alpha 2] None of these proposed coins were ever released for circulation through the Bank of Japan as they were trial or pattern strikes.[27][33][35] Twenty sen banknotes were last issued in 1919 and were allowed to circulate until their suspension on April 1, 1921.[36][37] By this time, efforts to re-establish the twenty sen coin were abandoned as silver bullion rose above their face value again.[27] Twenty sen coins were eventually demonetized at the end of 1953 when the Japanese government passed a law abolishing subsidiary coinage in favor of the yen.[38] Currencies of less than one yen were rarely used by this time due to excessive post-war inflation.[39]