Because a lot of forged gold and silver coins had circulated since the Edo period as coin casting technology was outdated and immature and they were used for trade settlement, a lot of complaints were made by foreign countries.
硬貨の鋳造技術も旧態依然の未熟なものであり、江戸時代以来、偽造金銀銭が多く流通しており、貿易決済にも用いられたため諸外国からの苦情が殺到。