In the Ming dynasty during the reign of the founder Emperor Kobu (Shu GENSHO), the use of metal coins was prohibited and all the money were switched to paper money (later switched again to Ginjo - silver coins used in China until early in the 20th century).
明では初代洪武帝のときに銭貨使用が禁じられ、すべて紙幣（後には銀錠）に切り替えられていた