After the issue of Nanryo Nishu silver coins in 1772, the amount of circulation of denomination silver coins with the unit of ryo (a base unit), bu and shu, began to increase, and in 1837, when Ichibu gin silver coins were issued, these coins came to surpass that of the currencies by weight, such as chogin, so silver coins were incorporated in the currency system of gold coin (koban).
の南鐐二朱銀発行以降、次第に両を基軸とする、分、朱の単位をもつ計数銀貨が増加し始め、1837年の一分銀発行に至って、丁銀のような秤量銀貨を凌駕するようになり、銀貨は小判の通貨体系に組み込まれることになった。