Ieyasu TOKUGAWA, who had won the Battle of Sekigahara, made the improvement of currency system one of the most important tasks before the foundation of Bakufu, ordering Shosaburo Mitsutsugu GOTO to cast Koban which were supposed to be circulated across the country.
関ヶ原の合戦に勝利した徳川家康は幕府設立に先立ち、貨幣制度の整備を重要課題の一つとし、後藤庄三郎光次に全国流通を前提とした小判の鋳造を命じた。