I'm going to japan in 2 weeks. What should i use in Tokyo?, Yens or dollars?

As others have said, Japan is an advanced country and to buy goods outside the airport you must use yen or credit cards. Japan is a safe place, generally, so it's fine to carry a large amount of cash. There's never a problem getting change. For example, if you buy a meal at McDonald's for $4 or so they smile and give you the change of 9600 yen.

Yen. Carry large amounts of it on you. (Seriously) I think the average old women I see buying a loaf of bread at the local mini-mart has about 40000 yen (400 dollars) on her. You do not want to be out somewhere and run out of yen. The ONLY ATMs that you can use an American bank card at are the Citibank ones. They are few and far between. (This is not a joke, you cannot use an American bank card at 97% of Japanese ATMs. It is strange I know as I can use my American bank card in Thailand, Korea, Singapore and Hong Kong with no problem but not Japan!)

Bring your credit card with you everywhere as a back up. But remember that Japan is primarily a cash based economy.

However, there are SOME places you can use American dollars (although I have no idea why you would want to do that). Sleazy bars outside American military bases will take American dollars. Some clubs/bars in the Roppongi district of Tokyo will take dollars. MANY hotels, restaurants, bars and so on in Okinawa will take American dollars. (This is because half of the island is occupied by the American military.)

P.S.

Don't come to Japan to do any serious shopping. It is cheaper to buy things in the US. For example, a jacket at the Gap in Japan is usually marked up an extra 40 dollars over the prices in the states.

Please don't expect Japan to be like some third world country where you can use dollars in a black market kind of context. This is the first world, so convert to yen. :-) (It's "YEN" by the way not "yens", e.g., 1,000 YEN.)

HOWEVER, the one exception to this is Akihabara, the famous electronics store area. Here, you CAN use dollars in many of the larger stores. Akihabara is sort of a special duty-free zone within the city. (see link below) So if you like, you can keep some dollars handy if you're in the market for electronic gizmos. Keep in mind that the prices are not always so different from American prices, though sometimes you might be able to wrangle a discount or two. (Also, credit cards are welcome in large shops in Japan--but your credit card co. will likely tack on a fee for any foreign purchases.)

Lastly...dude (dudette?), get out of Tokyo if you can. :-) It's like visiting New York City and thinking that you've experienced the USA. Good luck.

Yen of course! Would you like it if a question read "I'm going to the US, should I use yen or dollars in LA?"??? There may be some stores which will accept dollars, but I have to warn you that they will do so using their own 'exchange rate' which will NOT be favourable to YOU!

And please don't believe that the Japanese can in any way be 'bought' with dollars - especially a single dollar! That's downright insulting!

Yen

Yen, because it's Japan. :) Stores in Tokyo won't accept foreign currency.

Yen! (when in Rome do as the Romans do)everyone has given you great advice please make sure you exchange your money before you leave and set a spending limit. shopping in tokyo you'll rarely find some awesome deal (maybe on digital cameras) but thats about it.

Yen only. No one accepts dollars. Credit cards are ok, though.

You should bring dollars and exchange them for Yen. Dollars aren't tipically accepted in stores and other places.

You must use yen coz nobody accept dollars when you buy things.