You could e.g. send JPY to Bitstamp if Bitstamp's bank offer a better JPY to USD exchange rate than yours.  And it is pretty good, IMO.  Less than 1% loss there.  Exchange fees (0.5% or less x 2) and SWIFT transfer fee (fixed sum) are going to be the main expenses.  Not much for a large enough sum.  8000 USD or more, and you should be able to get away with less than 2% in fees.  The BTC/JPY rate may be up to 2.5% worse than BTC/USD, but usually the difference is smaller.  Sometimes the BTC/JPY rate is even better than BTC/USD, but probably not at high volume.