Luck

A very famous water doohickey thing in the famous white rock garden of Kyoto, of which I for get it's name. The old style 5y coin was shaped after it, the modern coin has a circular cut-out in the middle as it gives strength to the coin. The coins have a hole in them to allow spirits to travel through them, it makes the 5y and 50y coins 'lucky' coins that you should give to shrines and attach to wishes.

Kyoto, Japan.