"The Japanese Yen has throughout the history has always been very popular with numismatic collectors worldwide with its well-struck and beautiful intricate dragon design.
While the period of the Far East Pacific War, large numbers of these coins were melted down for the Imperial Japanese War efforts, which hence results in limited mintages surviving today from original historical official minting quantities.
The word "YEN" stands for "a round object" and across the years since the new Yen coin's (1871) introduction to replace the Tokugawa coinage of Mon, it has gone through several iterations of difference sizes and weights.
The first Yen comes in at a size of 38.5 mm & weights in at 26.96 grams. In the latter years, Yen was minted at a size of 38.6 mm and weights in at 29.96 grams from 1874-1887. And from the Meiji period of 1886-1914, the Yen has a reduced size of 38.1 mm and weights in at a reduced 26.96 grams."