Japan, 1819-1828, Koban, JDNA 09-20 C#22a Bunsei

The koban (小判) was a Japanese oval gold coin, cast on the order of Tokugawa Ieyasu in Edo period (Keichō era) feudal Japan and a part of Tokugawa coinage.^[1][2]

Minting of koban, Ōban and other coins began in year 1601 (year 5 of the Keichō era), signifying the beginning of the Tokugawa coinage.^[1] The Keichō era koban was issued with a face value of one ryō.^[2][3] Despite the existence of other gold and silver coins at the time, through a series of reforms the Bakufu managed to stabilize the koban to ryō 1:1 valuation by the end of the seventeenth century.^[3]

Nowadays, gold-foil cardboard versions of koban are sold as Engimono (縁起物, talisman/lucky charm) at Shinto shrines.