In Mario Kart 7 for the Nintendo 3DS, there are several characters that you can unlock, primarily by beating certain cups in the 150cc difficulty.
Here are the characters you can unlock, and what you’ll need to do to unlock them.
Daisy – Get first place in the Mushroom Cup on 150cc
Honey Queen – Get first place in the Banana Cup on 150cc
Lakitu – Get first place in the Lightning Cup on 150cc
Metal Mario – Get first place in the Special Cup on 150cc
Mii – Get first place in all cups on any CC
Rosalina – Get first place in the Star Cup on 150cc
Shy Guy – Get first place in the Shell Cup on 150cc
Wario – Get first place in the Flower Cup on 150cc
Wiggler – Get first place in the Leaf Cup on 150cc