As the currency unit of gold coins, ryo was established by Koshu-kin (the gold coin minted in Koshu Province), which Shingen TAKEDA ordered to coin, and handed down to the Edo bakufu (Japanese feudal government headed by a shogun); 1 ryo was equalized with 4 bu, or 16 shu (bu and shu were former Japanese currency unit).
金貨の通貨単位としての両は武田信玄により、鋳造を命じられた甲州金により確立され、江戸幕府に継承されたもので、1両は4分に等しく、また16朱に等しい。