When a villager's in boxes, he/she can be claimed to someone by wifi / local multiplayer / streetpass. Trading villagers is more specific than that, but generally it's just letting someone come over to get your villager, and vice versa.
When a villager's in boxes, he/she can be claimed to someone by wifi / local multiplayer / streetpass. Trading villagers is more specific than that, but generally it's just letting someone come over to get your villager, and vice versa.