I've only started toying around with CFW's and emulators on my N3DSXL and want to play a game of Jump Ultimate Stars with a friend via its Download Play multiplayer feature. I wanted to know if anyone has tried using said feature to play against a vanilla DS(i) or 3DS, or if you got the feature running but only by having both systems CFW'd (indicate what the two systems were and if they were running CFW or vanilla). Since DS(i) games and 3DS games come in the same cartridge form I don't see why no one could have tried this idea with a legit cart and a Japanese import system running the game. If this seems like an impossible idea would it be okay to explain why?
