Ansei Ichibugin

FACTTo stop the outflow of gold, the shogunate issued the Ansei Nishugin (June 1859, 85% fineness) just before the ports opened, making the silver in two nishugin (1 bu) roughly equal to one Mexican dollar. Western nations protested that this lowered the value of the dollar in Japan, and the shogunate stopped issuing it (catalog).^[1]

FACTHaving stopped the Ansei Nishugin, the shogunate melted down Mexican dollars and issued the Ansei Ichibugin (August 1859, 87% fineness) for exchanging them (catalog).^[1]

FACT"Yōgin" were foreign silver coins used in trade; those entering Japan were mainly Mexican dollars. Under the Japan–US Treaty of Peace and Amity (1854) one dollar was set equal to one ichibugin. Later the first US consul general Harris insisted on exchange by the same kind and weight, and one dollar became three ichibugin (Currency Museum, "Nihon Kaheishi").^[3]

FACTIn 1859, fearing an outflow of gold after the ports opened, the shogunate issued the Ansei Nishugin, which contained more pure silver than the Tenpō Ichibugin, on the day before the opening and tried to exchange one dollar for two nishugin. American opposition kept the rate at one dollar to three ichibugin (Currency Museum, "Nihon Kaheishi").^[3]

FACTAt the time 1 g of gold was worth about 5 g of silver in Japan, while abroad 1 g of gold was worth about 15 g of silver; gold was therefore cheap in Japan and flowed out of the country in quantity. Foreign merchants exchanged four dollars for ichibugin and then for koban in Japan, and exchanging the koban abroad yielded twelve dollars (Currency Museum, "Nihon Kaheishi").^[3]

FACTIn 1860 the Man'en recoinage cut the gold content to one third and brought the gold–silver ratio to the international level, ending the mass outflow of gold (Currency Museum, "Nihon Kaheishi"). The catalog likewise notes that the recoinage reduced the weight of gold coins to one third, bringing the domestic ratio in line with that abroad (catalog).^[3],[1]

INTERPRETATIONWeight, dimensions, mintage, surviving numbers, the classification of varieties by calligraphy or marks, and identification cues are not yet confirmed in the sources consulted for this record. They will be added as they are confirmed.