The Nintendo 3DS contains a mechanic called the StreetPass. It works like this: If you have a 3DS in your pocket and you walk past a dude with a 3DS in his pocket, weird things happen to your 3DS. (And his 3DS, but you don't care about him.)
Now, I understand where this is coming from. Japan has about 337 people on each square kilometer. Tokyo alone has 13 million people there. But the problem is, I'm not Japanese. I'm from what one would describe as "grim-up north" where the average population is 15 per square kilometer. I have relatives living on the countryside and I take trips to the wilderness every summer. StreetPass is useless here.
Heck, I'll probably multiply my Mii Plaza population several times when I go to the next con kept here. And if I ever visit Japan, I would multiply it again, because the cons here are small.