^That's sick, considering Ayu is working on reaching 50mil in total sales, counted throughout her entire career with all her releases added up together.
As much as wikipedia can be trusted... they have a compiled list of the highest selling albums, world wide.
http://en.wikipedia.org/wiki/List_of...bums_worldwide
Here's one for singles, as well.
http://en.wikipedia.org/wiki/Best-se...gles_worldwide
Don't trust those blindly, but they do actually give a quite accurate view of how it looks. No Japanese artist is even close to entering any of those two "charts".