Japanese Yen is the currency of Japan. In Japan, banks, post-offices, some major hotels and airports handle money exchange. Whether or not you must exchange your money before entering Japan depends on the type of currency you have. As the US Dollar is a highly traded currency in Japan, you will get a favourable exchange rate for it. However, this does not hold good for other competitive currencies. It is useful to know that ATM’s in Japan don’t usually allow the use of foreign-issued cards. However, exceptions to this rule are the ATM’s found at post offices and convenience stores.