If you want my take, getting a different region copy and game would depend on whether you want to catalog items separate to rach one in the other, especially the seasonal events - and indeed, Japan has loads of them. Having said that, I don't think you'd be missing out on too much unless you don't know anyone who has a Japanese copy of the game.
I also suggest you read other opinions in this thread as they come - all could be for different reasons, from fans of the game at varying levels of passion. (Geez, that sounded wrong...)
If you want to experience the exclusive holidays and you have an understanding of written Japanese (I think it would be difficult to play the game if not) then it might be, apart from the holidays the game is the same though. If you're just after the exclusive items it would be better to buy them here tbh.
For me personally I'd only buy a Japanese console if I wanted other exclusive to Japan games, seems a bit of a waste for just the one game.