1 Mon 'Kan'eitsūhō' Gold

The Kan'ei Tsūhō series, produced overwhelmingly in copper, occasionally appeared in gold and silver as presentation or ceremonial pieces rather than circulating currency. The 1657 date places this squarely in the year of the Meireki Fire — the single most destructive fire in Edo's history, which destroyed roughly two-thirds of the city and killed an estimated 100,000 people. Emergency expenditure and reconstruction demands severely disrupted the Shogunate's finances that year.

The KM#- reference reflects how poorly these gold presentation-format mon pieces are catalogued in Western references. Confirm attribution against Japanese specialist literature before pricing.