1 Shu 'Bunsei Isshukin'

The Bunsei Isshukin was authorized following a broader monetary reform under the Tokugawa shogunate, itself a response to the chronic debasement cycle that had plagued Japanese gold coinage since the Genroku era. By the Bunsei period, the shogunate's finances were under sustained strain — the eventual Tempo reforms of the 1830s were a direct consequence of the fiscal pressures already visible during this issue's production window. At .123 fineness, this is among the lowest-purity gold shu coinages in the Edo sequence.