The Streetpass Mii Plaza is some of the Nintendo 3DS's built in software that is meant to go hand in hand with the Mii Maker.
Uses StreetPass Technology and Nintendo Zone locations to gather Miis from other 3DS's and the Internet during event occasions (Spotpass) And at Nintendo Zone location you get 6 street passes from the last 6 peoples
Stores data on every Mii that has been StreetPassed, and will update changes on every subsequent SteetPass
Choose which Mii to greet other Miis and what Hat/Costume they will wear.
Choose a bio (Greeting, Likes, Dreams etc) to show others.
Puzzle Swap (Updated Occasionally with new puzzles)
Streetpass Quest I/Find Mii (Battle Entities for hats and save your king/queen)
Streetpass Quest II/Secret Streetpass Quest II (Included with first update and secret quest is locked untill full completion of normal Streetpass Quest II)
1st Major Update
At one point, StreetPass Mii Plaza recieved a large update that made various changes to the application.
Addition of 4 new DLC Games
Massive increase in Music variety
Added 99 new hats
Addition of Slide Show for viewing completed Puzzle Swap panels
Addition of StreetPass Map for tracking locations of met Miis
Addition of Accomplishments
Free Pixel-Mario Hat for those who update Streetpass
Access to various games is at bottom screen for convenient use
Added shop, coupon shop, game screen (fountain with game icons) & update widget to selection.
Choose from 6 emotion types while greeting other miis. (Found in greetings menu)
2nd Major Update
Starting with the release of the update in Japan on April 1st, 2015 and worldwide April 16th, 2015, the following additions and changes were made to the Plaza.
Game Pack 2, which includes Ultimate Angler (Streetpass Fishing regions outside of America) and Battleground Z (Streetpass Zombies in regions outside of America)
Adds the VIP Room and Streetpass Birthday to the main menu (have to purchase Premium to use). Additional Tickets can be earned from Streetpass Birthday.
Updates to Game Pack 1
Find Mii II: Adds the Usagi Support option to the main menu (allows the Streetpass Usagi to help the player at the cost of Coins) and the ability to see what Hats you haven't collected on the Map (by holding X while you can see the Map)
Flower Town: Can now hold R to auto-read text. Holding R to fast-forward during Harvesting has been sped up.
Mii Force: Can now skip the level intro, level ending, and cutscenes by pressing B.
Additional Hats and Suits to buy with Tickets
New dreams for the future have been added to the profile menu, for Streetpass Zombies' release.
Adds Speech Bubbles, which are unlocked through Tickets to customize your Streetpass greeting.
Each of the 8 games you have access to in the Plaza give you a free Speech Bubble themed for them, in addition to a Thought-bubble and an Streepass Usagi-themed ones given for free for updating
Adds the Play Selector option to the main menu, allowing you to remove games from the Plaza (this does not uninstall them) and then restore them in any order, as well as allowing you to play them directly from it's menu.
Games not actively in the Plaza will not be included when loading Streetpass Plaza with new Miis and it checks for games you haven't played yet, allowing you to ignore the games you have finished or don't play any more.
The Music Gallery is updated to include the new music tracks
Puzzle Swap: The player collects pieces to 3D pictures by Streetpass and Play Coins.
Find Mii / Streetpass Quest: Hire heroes or use accumulated Miis to fight enemies in a turn based RPG fight to earn hats.
Find Mii II / Streetpass Quest 2: The sequel of Find Mii. To unlock you Will Need To complete Find Mii twice.
Mii Force / Streetpass Squad: Command a team of Miis and mercenaries against the Gold Bone Gang.
Flower Town / Streetpass Garden: Become a master gardener and grow plants.
Warrior's Way / Streetpass Battle: Build an army and conquer the world.
Monster Manor / Streetpass Mansion: Battle supernatural entities as you escape a haunted mansion.
Ultimate Angler / Streetpass Fishing: Catch fish while hunting the Legendary Fish.
Battleground Z / Streetpass Zombie: Save a city under attack by zombies.
The background music changes in milestones for how many Miis you collect. It changes at 20, 50, 100, 300, 500, and 1,000 Miis, including your Mii.
First update included Streetpass Quest II and Secret Streetpass Quest II which included many new entites and many new hats to earn.
Upon release of the first major update, the shop was glitched preventing anyone from purchasing the DLC until it was updated shortly after release.