Your local bank should be able to help you with 
that and will quote you exactly what their 
current rate is.

The larger the bank, the easier it will be. For 
example, I would imagine in most banks in NYC or 
other large financial centers, it would be rather 
easy. In other smaller places, I think you have 
to put in an order and wait to get your money. 
Banks also usually charge something to exchange 
US dollars into yen (although this might be 
reflected in the exchange rate they give you).

Good luck,

Wendy