Some of the sellers Domingo mentions here are not Japanese based, they are Chinese based, but they are indeed honest and reliable and when they say they are selling 100% Japanese they are being truthful. The thing to watch out for with Chinese based sellers is that they sometimes sell "promo" CDs (in the Western sense - that is they are marked in some way such as this release which has a stamp burnt into the CD and a sticker on the barcode).

I have found that it is always best to ask Chinese sellers if each item is a promo. They often tell you but sometimes forget or simply make a general statement that some things they sell are possibly promo. If you care (I do) then always best to ask rather than having the hassle to return them (or whatever).

I have had dealings with most of the Chinese sellers listed above with no major problems.