I've got a Japanese Wii (yeah, yeah - ok ) and just purchased the Japanese version of the game.
I've not even attempted to play it yet, because I saw all this stuff about consoles being bricked. Now, although my console isn't modded, I did notice that people were saying you needed to be connected to the Internet as part of the upgrade process.
I would have thought that the update was contained on the Super Paper Mario disc itself as not everyone has an Internet connection. I don't have one where my Wii is at the moment.
Anybody know whether you have to have the Internet connection or not or should I be safe with just putting in the game and off I go?