 Fifty sen coins were first minted in 1870 during the reign of the Meiji emperor.The New Currency Act of 1871 stipulated the adoption of the decimal accounting system of yen (1, 圓), sen (1⁄100, 銭), and rin (1⁄1000, 厘), with the coins being round and manufactured using Western machinery.Although mintages numbered in the hundreds of thousands, it was reported in 1904 that fifty sen coins were not commonly seen in circulation.