Earlier this week we got word of a free Pokemon game coming to the 3DS in Japan, but not a whole lot of details were available. Now thanks to a new official trailer, we have a few more bits of info. The idea behind the game is to amass Pokemon by way of StreetPassing, which you can then use to take on thieves.
The actual thieves will tie-in to the upcoming film. In other words, it's very similar to the Warlords StreetPass plaza minigame. Finally, those who own Pokemon X and Y will get a special unlock, as will those who take The Thieves and the 1,000 Pokemon to the theater when the new movie hits.