sen just lost but they are still the best in world

The one sen coin (一銭) was a Japanese coin worth one-hundredth of a Japanese yen, as 100 sen equalled 1 yen.[1] 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.