Changing money in Japan is fairly straightforward: choose your location (airport, bank, post office or hotel), indicate your desire, and fill out the brief form. The Japanese staff will assist you should you have any questions.
Decide your priority for changing money: convenience or the possibility of assistance. The exchange rates will not vary greatly between locations; however, if you are really pressed to find the best exchange rate, you should change your money at a major bank. Check for the "Authorized Foreign Exchange Bank" sign (always displayed in English).
Use the currency exchange window at the airport if you desire convenience in terms of speed.
Use a bank if you think you will need help filling out the forms or if you're seeking a marginally better exchange rate. The half-page form should be in both Japanese and English, though, and require little in the way of explanation.
Use the post office or your hotel's front desk only if those place provide money exchange services. Not all post offices and hotels do this.
Whichever place you do decide to use to exchange money, you will need to indicate your purpose and fill out the necessary forms. Go to the window or counter and say, "riyoogai shitai n desu ga" (I wish to exchange money).
Tell the attendant which type of currency you wish to exchange. The attendant will then give you the appropriate form.
Write your name, address and phone number at the top left of the form. If the appropriate place on the form is not clearly marked, or is written only in Japanese (unlikely), then ask an attendant: "namae wa doko de kakimasu ka?" (Where do I write my name?" After that, the person will show the appropriate place to write everything.
Write the name of the hotel you are staying at if you don't have a more permanent address. The attendant will ask for clarification if there is a problem.
Write the number and types of bills you are exchanging. The space for this should be below the place your wrote your name, address and phone number. There will be a list of different denominations of the currency you have. Write the number of bills of each denomination you wish to exchange. At the bottom, write the total number of bills and total value.
Sign the bottom of the form and pass it to the attendant. You will have to show your passport (or alien card) at this point. In every location except the airport, the attendant will indicate a place for you to wait while the transaction is being performed. The attendant will then call your name and you can pick up your money.
