There are no visa requirements for travelers from the USA, UK or Canada going to Japan. You will be granted a "visa free" stay of up to 90 days. Your passport must be valid for the entire time you are staying in Japan.
Any international travel requires the use of a passport. If you do not have a passport it is important to apply for one as soon as possible. It often takes four to six weeks to process the paperwork for a passport (and even longer during the peak travel season of March to August).
For questions about obtaining or renewing your passport (American citizens) you can visit travel.state.gov.
* If you have a passport, please note - it is highly recommended that your passport be valid for up to 6 months after your scheduled departure date
* It is also important that you have at least one completely blank page (with no stamps or visas) in your passport. This is a requirement for entry into many countries. If your passport is nearly full it might be a good idea to apply for additional pages.
* If you are a U.S. citizen, we recommend working with G3 Visas and Passports to make the process smooth and easy.
Make several photocopies of your passport. Leave a copy at home with your family and carry a copy with you at all times when you are overseas for identification purposes, money changing, etc. If you should lose your passport, having a copy will speed up the process of replacing it.