1x Bunsei Era Gold 1 Ryo (1819-1828) 1x Certificate of Japan Numismatic Dealers Association A Japanese gold coin from the Edo period. In the currency system of the time, this was equivalent to one ryo. These coins circulated primarily as a means of payment between samurai/daimyo and merchants in the high-priced trade of feudal Japan. The gold coin comes with a certificate of authenticity from the JNDA.