Yen comes in several different dinominations, both paper and coin. The image to my right shows coin currency, ranging from 1 yen to 500 yen. Before the American recession, there was an approximate 1:1 ratio between yen and dollars. Now, according to Yahoo's currency converter, $1 is equivalent to 76.455¥. Unfortunately, that means that I lose more than 20% of every dollar I convert to yen.
Take a look at the image on your right. That big coin at the bottom, the one that says "500" on it? That coin is worth more than $5 in US currency. Psychologically, I am not fit to spend this kind of money. I've lived for 25 years in a country where anything that jingles in your pocket is practically worthless.
Equally hard to remember is that yen isn't calculated with decimals to divide cents and dollars. $20.25 equals "One thousand, five hundred and forty-eight yen." Few times in my life have I been about to say I've had a thousand of anything in my pocket. It almost makes you feel like a rich man. That is, until you realize 1548¥ isn't even enough to buy dinner and a movie in Japan. Well, at least I have my health.
Paper money comes in four increments: 1000, 2000, 5000 and 10000¥. Japan is a cash-based society, so even mom-and-pop stores can break 10000¥ bills. In America, you'll often find cashiers don't carry enough change to break anything larger than $20. "Large quantities of yen are often counted in multiples of 10,000 in the same as values in Western countries are often quoted in thousands (3).