[masaegu]

You can remit the amount necessary to your own U.S. bank account through the Japanese post office for a fee of 2,500 yen. Bring your Japanese ID. (I'd bring a few just in case.)

With the exception of CitiBank, where the fee is 2,000 yen, the fees charged by major Japanese banks for the same service are much higher, making using the post office a pretty smart choice.