Initially, we recommend that you translate using the tools provided by Amazon.
If you already sell on Amazon.com (US), you can use that listing on Amazon.co.uk (UK). However, if your listings are listed in 4 other European marketplaces that use languages other than English, you will need to translate the listing for that ASIN.
Amazon's Build International Listings (BIL) tool allows you to use your existing listings (in this example, on Amazon.com) in Europe so you can quickly prepare your listings for the 5 marketplaces in Europe. This tool is not intended for translating listings, but if you have already translated listings, it will help you to review those listings.
You will be able to find untranslated Japanese listings from among listings for European marketplaces. When translating, you can use Amazon's translation services or external translation companies.