[Sangetsu]

If you have the Google toolbar, you should be able to translate the pages at Yahoo Auctions. The translations aren't great, but good enough for you to get the basic details.

To get a user name and set up a payment account you'll need to know a fair amount of Japanese. The sign-up pages are secure, and you cannot use the translation feature on them. If you can't find your way through them, you'll need to find a Japanese speaker that you trust to help you with it.