Meiji coinage (1870–1912)

Ten sen coins were first struck towards the end of 1870 (year 3 of Meiji) from a newly established mint at Osaka.^[2][3] Initially, this process was done by engineers from the United Kingdom as Japan did not have the technology or raw materials to manufacture new coins.^[4][5] Authorization was given to strike ten sen coins in .800 silver, weighs 38.6 grains (2.5g), and has a 18.28mm diameter (0.72 in).^{[6][7][lower-alpha 1]} The first design used is nicknamed rising sun dragon (旭日竜, Asahi Ryu), which had its features engraved by a commission of Japanese artists.^[4] The obverse side features a dragon with an open mouth, while on the reverse there is a paulownia decoration with a sunburst in the center, and the chrysanthemum seal up on top. While dated 1870 (year 3), these first year ten sen coins were not released into circulation until the following year (1871).^[4] During this time, the coins along with twelve other denominations were adopted by the Meiji government in an act signed on June 27, 1871.^[10] This newly adopted 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] Ten sen coins were set as legal tender only up to the amount of 10 yen which was fixed by government regulations.^[13] An issue soon arose when the weight of silver ten sen coins per face value became too light in regard to the higher valued silver 1 yen coin. An amendment to the currency act (Daijo-kan Declaration No. 74) was adopted in March 1872 (year 5) which intended to increase the weight of the ten sen coin. This action was never carried out, and the currency act was amended again in the following year.^[4][14]

Changes in weight and design features of the ten sen coin was implemented in 1873 (year 6). While their diameter remained the same, the coins had their weight increased to 41.6 grains (2.69 grams) as proposed in Declaration No. 74.^[7][15] The second used design has a "western style" medallic orientation, with 10 SEN in Arabic below the dragon on the obverse side.^[16] On the reverse are leaves of paulownia and a chrysanthemum seal up on top with the value "10 sen" written in Kanji.^[15] Ten sen coins continued to be minted with this design until at least June 30, 1879.^{[17][18][19][lower-alpha 2]} Only proof strikes were made for coins dated 1880 (year 13) for exclusive use in presentation sets.^[20] Production resumed in 1885 (year 18) and continued through 1897 (year 30). While Japan officially went onto the gold standard during this year via the coinage act of 1897 (Meiji 30 Law No. 16), this had no effect on the ten sen coin which continued to be produced unchanged until 1906 (year 39).^[15][21] An amendment to the 1897 coinage act was implemented this year which gave ten, twenty, and fifty sen coins new designs. This replaced the second dragon design which had been in place for 33 years.^{[lower-alpha 3]}

The third ten sen design features a wreath on the obverse with the value written in kanji in the center, and a sunburst surrounded by flowers on the opposite side (reverse). Almost immediately there was a problem during the design transition when the market price of silver exceeded the face value of the ten sen coin.^[22] Coins dated 1906 (year 39) were originally made using two different designs. The second older dragon design was used for coins produced until March, while the newly adopted third design was used for coins produced from June 1906 to January 1907.^[23] The latter of these coins had been distributed to the banks but not released yet when another amendment to the coinage act was made in March 1907.^[23] Ten sen coins by law had their silver content lowered from .800 to .720, and their weight from 2.7 to 2.3 grams. The 1906 dated coins which had been minted using the third design were all melted except for one which is preserved at the Japan Mint.^[24] Adjusted coins with the third design were finallu released into circulation when 1907 (year 40) dated coins were produced in August of that year.^[23] These continued to be minted until the death of Emperor Meiji in 1912 (year 45).

Taishō coinage (1912–1926)

Production resumed under Emperor Taishō in 1912 and World War I broke out two years later. This event brought Japan a booming economy which required an increase of small denomination coins. Unfortunately, rising silver bullion costs to produce ten sen coins also became an issue again.^[25] Ten sen coins were struck in silver until the end of 1917 (Taishō year 6), when an announcement was made to replace the coins with fractional bank notes.^[25][26] The coinage act of 1897 was amended again and went into effect on May 1, 1918 providing coinage as needed.^[27] Ten sen coins dated 1918 to 1922 (year 7 to 11) were produced in silver under this amendment and stored at the Bank of Japan.^[28] For reasons unknown these coins were never exchanged for ten sen notes, and possible reasoning depends on the literature used.^[22] It remains debatable if these coins were ever meant for circulation at all as they could have been intended as trial or pattern strikes.^[29] Most of these were eventually melted down at the mint into bullion and shipped overseas by 1923 (year 12) leaving ten examples behind at the mint.^[24][30]

Ten sen copper nickel coins were authorized by the Imperial ordinance of August 26, 1920.^[31] These coins weigh 57.86 grains (3.75g), have a 22.12 mm diameter, and a 4.55 mm central hole.^[28][32] The chosen design features a chrysanthemum seal, and a bouquet of paulownia flowers on the obverse, while the reverse side uses Qinghai waves.^[33] This same ordinance also reduced the size of the 5 sen coin due to public complaints regarding the similarity of the two coins.^[31][32] Ten sen copper nickel coins were eventually produced in large amounts which peaked in 1922 and 1923 (year 11 and 12).^[30] This was done to encourage the public to redeem old ten sen notes for coins, which lasted into the Shōwa era.^[30] No additional changes regarding ten sen coins were made during the remainder of Emperor Taishō's reign.

Shōwa coinage (1927–1946)

Copper nickel ten sen coins resumed production in 1927 (year 2 of Shōwa) and continued to be minted until 1932 (year 7). The "1897 coinage act" was then amended or a final time for political reasons in 1933 which left an impact on the series.^[34] The width of ten sen coins dropped slightly by 0.1mm to 22mm, and the weight was increased from 3.8 to 4 grams.^[34] Pure nickel was chosen as an alloy as an anti-counterfeiting measure because it was difficult to process with the technology of the time.^[35] Another reason has to do with the Mukden Incident in 1931 (year 6), and subsequent Japanese invasion of Manchuria. Nickel was being stockpiled as the metal was not produced in Japan, and could be used in the event of a larger conflict.^[35][36] The design of the nickel coins was chosen based on ideas solicited from the general public, and pattern coins were made.^[35][37] This design features the chrysanthemum seal and paulownia surrounded by arabesque on the obverse, while the reverse features a Qinghai wave design.^[35] These pure nickel coins substituted the old copper-nickel coins starting on April 1, 1933 (year 8).^[38] Production continued for another four years before the Second Sino-Japanese War broke out in July 1937 (year 12).

The National Mobilization Law was legislated in the Diet of Japan by Prime Minister Fumimaro Konoe on March 24, 1938 to prepare the country for war. This action led to the promulgation of the "Temporary Currency Law" which came into effect on June 1, 1938.^[39][40] It now became possible to change the material and purity of money without a resolution from the Imperial Diet. An aluminium bronze alloy consisting of 95% copper and 5% aluminium thus replaced ten sen nickel coins as nickel was needed for munitions.^[39][40] The only changes made to the coins other than their alloy was a new design and a smaller central hole.^[39] Waves along with a sunburst and chrysanthemum seal were chosen for the obverse, while the reverse features a grooved cherry blossom design with paulownia. These coins were only produced for two years before an increased wartime demand for copper caused another alloy change.^[39][41] Ten sen coins were switched to a pure aluminum alloy on March 28, 1940 (year 15) by Royal Decree No. 113.^[42] The size of the coins remained the same, while the light aluminum alloy cut the weight of the coins by more than half from 4 to 1.5 grams.^[43] These coins feature a chrysanthemum seal with leaves on the obverse, and a cherry blossom design on the reverse.^[43]

As the war situation grew worse for Japan, more aluminum was needed for aircraft. Ten sen coins had their weight lowered from 1.5 to 1.2 grams on August 27, 1941 by Royal Decree No. 826 to meet this demand.^[44] Things only deteriorated further when the Second Sino-Japanese War became the broader Pacific War three months later. The Japanese government eventually withdrew nickel and copper ten sen coins from circulation in December 1942, and exchanged them for aluminum ones.^[45] On February 5, 1943 by Royal Decree No. 60, more aluminum was taken out of ten sen coins by lowering their weight from 1.2 to 1 gram as the metal became difficult to obtain.^[46][43] An announcement by the Japanese government was eventually made in April 1943 regarding plans to replace aluminum coinage with tin.^[45] Aluminum was officially abolished for coinage by the end of the year in favor of the new alternate alloy.^[47] One of the main reasons for using tin centered around it being relatively easy to obtain from occupied territories in Southeast Asia. The decision was not made lightly, as tin was a strategic material which is unsuitable for monetary purposes as the metal is soft.^[48]

Ten sen coins with a tin alloy were enacted on March 8, 1944 by Royal Decree No. 388.^[49] These coins are reduced in size from 22 to 19mm, the weight was increased from 1 to 2.4 grams, and a central 5mm hole was added.^[47] The design used for these coins features a chrysanthemum seal and paulownia on the obverse, and inscriptions on the reverse. Production only occurred for a few months before being discontinued due to allied air superiority and control over the seas.^[50][48] The Japanese government issued Ten sen notes as a response when materials could no longer be secured for the coins.^{[lower-alpha 4]} Ten sen coins were brought back into production in December 1945 and were officially enacted on January 26, 1946 (Showa 21) with an aluminum alloy.^[51][52] These hole-less coins are the same weight and size as the previously made final 1943 issue.^[53] The final design employs symbols of Japan with rice ears and the chrysanthemum seal on the obverse, and cherry blossoms on the reverse.^[53] It was mandated at the time by the Supreme Commander for the Allied Powers that coins read "日本政府" (Nippon-koku, Government of Japan) rather than "大日本" (Dai Nippon, Japanese Empire).^[54] Their production lasted only two years before being discontinued due to a lack of remaining wartime supplies.^[53] Ten 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.^[55] Currencies of less than one yen were rarely used by this time due to excessive post-war inflation.^[56]

Meiji

The following are circulation figures for ten sen coins that were minted between the 3rd, and the 45th year of Meiji's reign. The dates all begin with the Japanese symbol 明治 (Meiji), followed by the year of his reign the coin was minted. Each coin is read clockwise from right to left, so in the example used below "二十三" would read as "year 32" or 1899. Some of the mintages included cover more than one variety of a given coin.

• "Year" ← "Number representing year of reign" ← "Emperors name" (Ex: 年 ← 二十三 ← 治明)

Taishō

The following are circulation figures for ten sen coins that were minted between the 1st and the 15th (last) year of Taishō's reign. The dates all begin with the Japanese symbol 大正 (Taishō), followed by the year of his reign the coin was minted. Each coin is read clockwise from right to left, so in the example used below "四" would read as "year 4" or 1915.

• "Year" ← "Number representing year of reign" ← "Emperors name" (Ex: 年 ← 四 ← 正大)

Shōwa

The following are circulation figures for ten sen coins that were minted between the 2nd, and the 21st year of Emperor Shōwa's reign. The dates all begin with the Japanese symbol 昭和 (Shōwa), followed by the year of his reign the coin was minted. Each coin is read clockwise from right to left, so in the example used below "二十" would read as "year 12" or 1937. Coin patterns that include examples struck on porcelain are not included here as they were never issued for circulation.

• "Year" ← "Number representing year of reign" ← "Emperors name" (Ex: 年 ← 二十 ← 和昭)