Sales of Western titles in Japan have been on the rise this generation. They obviously don't perform as well as they do elsewhere, but there's an emerging market that's comparable to Western audiences' consumption of lower profile Japanese titles (i.e. not Final Fantasy, Metal Gear, Nintendo, etc.).
In fact, Call of Duty, Uncharted, Grand Theft Auto, Skyrim, The Last of Us and so on have all managed 100,000 to 200,000 sales their first week, which is better than most domestic releases that aren't the aforementioned big names.