Japan is a cash-based economy, so it is a good idea to bring enough cash for initial expenses when you relocate here. The simplest way to cover this need is to bring real cash or travelers checks with you. As the exchange rate is much better in Japan than in other places overseas it is best to wait to exchange them here.
The best rate I have found for conversion is using a discount ticket seller such as Daikokuya. They do not charge any fees and only make a profit in the exchange rate, which is usually as good or better than banks.
Alternatively, you could open a Japanese bank account shortly after arriving and send an international transfer to yourself. For large amounts of money, this tends to be the safest and least costly way to move funds to Japan. If you intend to utilize this option be sure to check in advance whether or not your foreign bank account can send funds to a Japanese bank account, as some cannot.
If they can’t send funds, you can still send money using a remittance service. Basically, a remittance company has a bank account in the US where they receive the funds domestically before they sending them to your account in Japan on your behalf. Examples are below:
Since 2002, XE Money Transfer has processed more than $10 billion in global payments and served thousands of businesses and individuals.
Since 2000 OFX has managed over 1 million transfers, totaling in excess of AUD $100 billion. This service is recommended on a blog called Tokyo Cheapo and the link they provided (used here too) should allow you to waive the transfer fees normally charged on each transaction.
To decide which is best for you, check what your bank charges for international transfers (if they even offer it) and what their exchange rate is like. If you want to use a remittance service, it takes around a week or longer to set up and it is easier to do before you come to Japan, so we recommend to set it up as early as possible.