However the necessity for the trading vessels never faded because the development of money economy required a large quantity of copper coins in Japan, where coins were not cast in those days, and because the demands for Chinese products of culture including ceramic ware, pottery, and chinaware called 'karamono' (things imported from China) were still intense.
しかし、当時銭貨を鋳造していなかった日本では貨幣経済の発達に伴い、大量の銅銭を必要とし、また「唐物」と呼ばれる陶磁器を初めとした中国の文物の需要も依然旺盛で、貿易船の必要性が減ずることはなかった。