The game was brought to the West by Atlus (and later Namco Bandai in Europe) when Sony passed up the publishing rights. It's now one of the biggest exclusive titles in the PlayStation 3's line-up.
In fact, it's such a big deal that it's earned "Greatest Hits" status in the US and will be repackaged at a lowly $29.99. If you haven't checked it out yet, it's definitely worth doing so. The game's hard and demands a lot of patience, but it's very rewarding.