1 sen coin

The one sen coin (一銭) was a Japanese coin worth one-hundredth of a Japanese yen, as 100 sen equalled 1 yen. One sen coins were first struck for circulation during the 6th year of Meiji's reign (1873) using a dragon design. The denomination had been adopted in 1871 but coinage at the time could not be carried out. Aside from an alloy change and a new rice stalk wreath design, one sen coins remained the same weight and size for the remainder of the era. The situation changed when World War I broke out under Emperor Taishō as rising metal costs led to a size and weight reduction. These smaller coins were first produced in 1916 with a paulownia design which was seen as liberal at the time. Emperor Shōwa took the throne in 1926, and Japan was pushed into a militaristic regime by the early 1930s causing metals to be set aside for wartime conditions. These effects would later impact one sen coins through numerous alloy, size, and design changes.

Bronze was the first alloy to be used for coinage which was replaced by brass, then aluminium in the span of a single year (1938). One sen coins were made lighter and were reduced in size as World War II raged on causing a demand for material to make military supplies. The last coins were produced from 1944 to 1945 using a tin and zinc based alloy as the situation further deteriorated. One sen coins were discontinued after the war, and were demonetized at the end of 1953 along with other subsidiary coinage. Collectors now trade these coins on the market where their value depends on survivability rate and condition.