The national language of Japan is... Japanese. There's no need to worry if you're travelling to Japan on your gap year though, most Japanese people under the age of 40 will have studied English for at least six years. Often their written English can be better than spoken though, and so you might find it useful to write out what you're trying to say. In general Japanese people will go to great lengths to help a foreigner out.
Like English, there are a few different dialects and scripts in Japanese making it even harder if you're trying to do the right thing and learn the local language. Keep trying though!
You'll be using the Japanese Yen if you're visiting Japan on your gap year. Coins come in 1s, 5, 10s, 50s, 100s and 200s. The bills come in 1000s, 2000s, 5000s and 10000s.
Cash is still the most popular way to pay for things here, although cards are widely accepted in the big cities. Don't be surprised if you see locals paying for goods with their mobiles though, it all comes through on their phone bill - pretty cool hey?!
ATMs are known as cash corners in Japan - you'll find them at over 12,000 7-Eleven stores and the worldwide banks. Take note though, a lot of Japanese ATMs are closed at night and during the weekend.
Please note, some over-the-counter medications are prohibited in Japan and can get you in trouble, so triple check with your doctor before you leave. You may also require permission in order to import drug-filled syringes, such as EpiPens and the like too. Ignorance is not considered an excuse, and you can expect to be jailed and deported if caught.
Attempting to offer a tip can be seen as offensive in Japan, and the tipping culture doesn't really exist. Great news for budget backpackers - the price you see is the price you pay. The service in Japan is legendary and if you do leave a tip, the waiter will most likely come running after you to give it back.
Japan is expensive, probably a good thing you're not expected to tip really. There are ways to keep the costs down though. Check out the getting around Japan page for some top tips on saving money on travel for starters - the rail passes can save you a fortune. Get all your essentials from the 100 Yen shops too. Typical prices for moderate budget travel would be ¥5,000 for hotel, ¥2,000 for meals, and ¥2,000 again for entry fees and local transport.
The seasons are very different in Japan. Spring is one of the best times to be in Japan, so if possible aim for a gap year in Spring here. It's warm, but not too hot, and it's also when the beautiful cherry blossoms start to bloom. Visit Japan in the summer and you'll find a dreary rainy season in June which come July/August turns into a steam bath with extreme humidity and soaring temperatures. If you're visiting in Autumn beware of the typhoons and in winter you can make the most of the skiing and hot-spring hopping.
There is pretty much no chance you'll fit in in Japan. Whether you find yourself among the throngs of salarymen in suits, the gradeschoolers in uniforms, or the harajuku girls on the streets - it's too hard to keep up. Just accept it and enjoy the people watching opportunities while you're here.
Top tip: wear shoes you can slip off easily, Japanese people love a good pair of house shoes.
It's always a compliment when someone tries to learn your language - especially one as difficult as Japanese, so give it a go. You should also remember that bowing is big in Japan: men do it with their hands at their sides and women bow with their hands together in front. There are a lot of rules on how far to go for the Japanese, but for foreigners a simple 'token' bow will work fine.
If you're visiting a shrine or temple make sure to follow the appropriate cleansing procedure before you even think about going in. If in doubt - watch others first.