Mario Kart 7: How to Unlock Your Mii
You can unlock your Mii to race with in Mario Kart 7 for the Nintendo 3DS.
To unlock your Mii, you need to get first place in all cups on any CC. Obviously, 50cc would be the easiest to do this in.
Check out my full guide for all of the unlockable characters in Mario Kart 7.