StreetPass Mii Plaza

Easy PlayCoins
You can get more than 10 PlayCoins a day by changing the date under the system settings. You can earn one PlayCoin by taking 100 steps with the 3DS in Sleep mode. Two PlayCoins can buy either a Wandering Hero (Find Mii) or Puzzle Piece (Puzzle Swap).
Puzzle Swap
You must complete two separate puzzles by collecting pieces that other people have found in StreetPass adventures. You can get a puzzle piece from another Mii's puzzles to complete your own.
Personal greeting
StreetPass with the same person multiple times to get a personal greeting.
Miis
Each Mii collected through StreetPass becomes a "unit" that can be used in the dungeons. Each attack and progress made will carry over to the next time you enter Find Mii. If you StreetPass with the same person multiple times, that person's Mii will level up and become more powerful. The shirt color of your collected Mii units corresponds to the type of magic they use.
Black Magic: Darkness
Brown Magic: Summon a "wandering hero"
Green Magic: Next hero will gain extra power
Orange Magic: New heroes that enter will get a morale boost
Pink Magic: Heroes are "full of daring" and less likely to be scared
Red Magic: Burning flames (does extra damage against blue ghosts)
Yellow Magic: Sandstorm (lowers the chance of getting scared) and allows damage against enemies holding a yellow shield