Perhaps with a Japanese bank account you can withdraw for Gox. You may then be able to achieve your goal.
Seriously it is better much than US bank account, but it still takes about 2 weeks to withdraw to a Japanese bank account from my experience. Also there is daily limit for withdrawal. It takes so long to turn around. Unfortunately there is no competitive JPY-BTC market as buyers. So you may need to have other currency bank account. Luckily I have USD, EUR, GBP, JPY and CAD banks and always comparing
But like other FX, sports betting or similar market, if you consider transfer cost and risk, discrepancy is diminishing immediately.
there is a contradiction,
= If you'd like to have big gain, you should have bunch of capital principal and patience.
= You'll be in trouble to turn around big capital limited by each transaction limit and time to transfer.
Now arbitrage is even difficult with those conditions. You'll need to follow one direction (increasing or decreasing BTC) in long trend after all.