Besides, the currency system partially using quaternary (1 ryo was equal to 4 bu, and 1bu was equal to 4 shu.) was too difficult for foreigners to understand and its improvement was required.
また、1両が4分、1分が4朱という一部4進法が用いられる貨幣体系も外国人からは分かりにくく、改善が求められていた。