The official game website for Final Fantasy Crystal Chronicles: Remastered Edition is live and in among the high res images, info about the ‘Lite’ version – effectively a demo of the game – and a general ‘what’s what’ for the upcoming title, is an interesting note about the online multiplayer mode:
*In online multiplayer mode, a player will only be matched with others in the region specific to player’s software.Small print from the official game website
You’ll only be able to play with folk who are in the same region as you, and this goes for all versions of the game. Why this is the case is anyone’s guess but it’s also worth remembering that the game won’t feature an offline, local multiplayer mode which may be disappointing for some . You can read more about why the developer didn’t include offline multiplayer here.