Ōban
An Ōban was a monetary ovoid gold plate, and the largest denomination of Tokugawa coinage. Tokugawa coinage worked according to a triple monetary standard, using gold, silver and bronze coins, each with their own denominations.
gold coinage: Ōban, Koban, Ichibuban, 1601-1695.
The first Oban – Tenshō Ōban – were minted by the Gotō family under the orders of Hideyoshi in 1588.
The Tenshō Ōban was equivalent to ten Ryōs, or ten Koban plates, with a weight of 165 g.
