One of the features that made Dragon Quest IX a breakout success in Japan was trading treasure maps via StreetPass. So, of course Dragon Quest VII for Nintendo 3DS has StreetPass functionality built into it.
Jump explains players can trade stones with carvings on them. These stones are tied to a Monster Park and when you collect three StreetPass stones in one set you can make a monster appear in a cave to fight. A scan from Jump shows players fighting a giant slime. Players can discover all kinds of different monsters to fight using the StreetPass stone system.
Dragon Quest VII comes out on February 7, 2013 in Japan.