Passport
Of course, you always need a passport when traveling out of your home country, and if yours is nearly expired, you should get a new one before you leave. Many countries won't issue you a visa if you have less than six months left on it. Also, make sure that there are several empty pages left on it for entrance and exit stamps, it can be a hassle to have them added on if you run out. It's always a good idea to make a copy or two of your passport before you leave - in case you lose it. All visitors in Japan must have a valid passport for the duration of their stay in Japan, however only residents of certain countries need to apply for a visa in advance (see Visa section below). Visitors are required to carry either their passports or Alien Registration Card at all times. People staying more than 90 days (tourists included) are required to have an Alien Registration Card. The chances of being asked to provide aren't great, but if you don't have it, the dutiful officers will drag you down to the nearest police station where you'll get to spend the next couple of hours explaining yourself.

Visas
People from the USA, Canada, Argentina, Belgium, Denmark, Finland, France, Iceland, Israel, Italy, the Netherlands, New Zealand, Norway, Singapore, Spain, Sweden and a few others planning on staying in Japan for less than 90 days do not need a visa - just a valid passport. Citizens of the UK, Ireland, Austria, Germany, Mexico, and Switzerland can stay for up to 180 days without a visa. South Africans must have a 3-month visa to enter Japan and can apply for extensions for longer stays. If you are not sure of your country’s visa requirements, make sure you check before you leave your country.

Working holiday visas are available for Australians, Canadians and new Zealanders between the ages of 18 and 25 (sometimes 30). You must apply to get one; those granted are allowed a six-month stay and two six-month extensions. The idea is to allow young people to travel for an extended period of time while working part-time. In reality, many with this visa work full-time as well.

Note that those in the country with tourist visas are not allowed to work. Although this is commonly ignored, you will get deported if you are caught working. Many aspiring English teachers find jobs and temporarily work with a tourist visa and then make a visa run to a nearby country once they find a company to sponsor them. South Korea is the most common (and cheapest) destination, although any country that has a Japanese Embassy is OK. If you're looking for a close tropical alternative, Guam or Saipan make for a good quick trip.

If you need a visa extension, you’ll have to go to the local immigration bureau and fill out the required documents. You must then return the along with your passport, passport-size photographs, an application fee and a letter explaining your reasons for extending your stay. You may also be asked to show proof of sufficient funds and a valid return ticket out of Japan. The alternative is to make a quick trip out of the country (the cheapest being South Korea) and then return to Japan. You will get question by immigration officials when you arrive, but they normally let you back in without much trouble. Remember that even if you have a valid working visa, you must go to your local immigration office and get a re-entry permit before you leave, or technically you will not be able allowed to re-enter the country. You can apply for a single re-entry permit or a multiple re-entry permit that allows you to leave the country as much as you like (for 1 year).

Driver’s License
If you plan on doing any driving in Japan you'll need to get an international driver's license before you arrive. This is valid for 1 year, after which you will need to get a Japanese license if you wish to continue driving in Japan.  In either case, you will also have to have a valid driver's license from your home country. Remarkably, all you have to do to get an international driver's license is pay a small amount at the appropriate agency in your own country, show your valid driver's license, and let them know when you want it to begin from. International driver's licenses are good for one year.

Customs
Visitors are allowed to bring 400 cigarettes (100 cigars) or 500 grams of tobacco; three 760 ml bottles of alcohol; 2 ounces (57 grams) of perfume; and gifts and souvenirs up to or equal to Y200, 000. Firearms, drugs and pornographic material will be confiscated if your bags are searched. While on the plane you'll be given an immigration form and a customs declaration to fill out. If you are within the duty free allowances mentioned above, you can ignore the customs form.

Note that if you are arriving from a third country you will also have to fill out a yellow health form which asks you to detail any illness you may have suffered in the last two weeks. If you haven't had any health problems, you can ignore this as well.

Osaka