2 Shu 'Ansei Nishugin'

The Ansei Nishugin was struck in direct response to a currency crisis triggered by Japan's forced opening to foreign trade under the Harris Treaty of 1858. Foreign merchants quickly recognized that Japanese gold was undervalued relative to silver by international standards — roughly 1:5 domestically versus 1:15 globally — and began arbitraging gold out of the country at an alarming rate. The Shogunate debased its silver coinage to counteract this drain, and the Ansei Nishugin was part of that emergency monetary response, its fineness reduced from the earlier Ansei issue struck just months prior.

The piece circulated for only a few years before the Meiji Restoration upended the entire Tokugawa monetary system.