The 1-yen coin (一円硬貨, Ichi-en kōka) is the smallest denomination of the Japanese yen currency. The first Japanese one-yen coins were made of both silver and gold in the early 1870s. Issues facing the Japanese government at the time included wanting to adopt the gold standard, and competing against the Mexican dollar for use in foreign trade. The decision was made to use silver one yen coins exclusively outside of Japan for trade, while gold coins were minted and used in mainland Japan. Gold and silver coins were eventually allowed to co-circulate in mainland Japan from 1878 to 1897 when they were demonetized. Millions of former one yen silver coins were countermarked by the Japanese government for use outside of the mainland. Silver one yen coins continued to be minted until 1914 for backi