I recently and randomly picked up a Japanese book, 1Q84. I was enjoying it quite a bit, when I started thinking about the cultural references it contained - it has numerous references to Western classical music and Sean Connery. It worried me that they might have actually replaced Japanese music and actors with western "equivalents". But of course, there has been a great deal of cultural cross pollination, so it is no more unusual for a Japanese person to be aware of Sean Connery or The Brothers Grimm than it is for me. I didn't want to spoil the book by reading reviews before I read the book itself, but I skimmed enough to gather the Sean Connery part, at least, seems to be original source material.
Part of the attraction in reading a book like that is the fact that it is a Japanese book. It feels demeaning to have take that away because they worry the foreigness of it will be disturbing or unwelcomed by American readers.