Koban (coin)

A koban (小判) was a Japanese oval gold coin of the Edo period (1603-1868). It was a unit of currency and represented a significant denomination, typically worth one ryō. The koban was introduced by Tokugawa Ieyasu as part of his currency standardization efforts. Its value fluctuated over time relative to other forms of currency, such as silver and copper coins, due to economic conditions and alterations in the gold content by the shogunate. Different types of koban were issued throughout the Edo period, each with varying weights and gold content, reflecting attempts to manage the economy. The koban was primarily used for large transactions and by wealthier individuals, serving as a symbol of wealth and status. The koban was withdrawn from circulation after the Meiji Restoration in 1868, when Japan adopted a new currency system based on the yen.