they are the first 50 yen coins to be released. in 1959, it was too similar to the 100 yen coin, so they pierced a hole in it to make it more distinguishable from the 100 yen coin.
they are the first 50 yen coins to be released. in 1959, it was too similar to the 100 yen coin, so they pierced a hole in it to make it more distinguishable from the 100 yen coin.