Koban

The Koban's oblong shape wasn't just for show; it allowed for efficient stacking in Edo-era storage chests, a practical nod to Japanese carpentry traditions.

This gold coin, minted from the early 17th century through the mid-19th, served as the backbone of trade in a period of relative isolation. Values varied by weight and purity, often leading to disputes at markets. Early issues came from mines in Sado and other regions, though exact sources shifted with political control.

Production methods involved hammering gold into those distinctive oval forms, sometimes recycling scrap metal. We don't know the precise mintage figures—records were spotty even then. Counterfeits were common, which kept numismatists like me on our toes.

A forger's attempt at a Koban once fooled a daimyo, but that's another story.