In the Meiji period, yen was introduced as the currency unit, however, '1 yen was equivalent to 1 ryo' in changeover phase, so 'yen' was called 'ryo' for a while.
明治時代に通貨単位として円(通貨)（円）が導入されたが、切り替え時に「1圓は1両と等価」とされ、しばらくの間は「圓」のことを「両」とも呼んでいた。