Mii

Miis are customizable characters that were debuted alongside the Wii via the Mii Channel, the Nintendo 3DS and the Wii U via the Mii Maker. Their name is obviously a reference to the name of the Wii and the fact that the character can reflect the player (and of course others as well). They've since become a phenomenon and arguably the mascot of the console excluding Mario.

Once the player has created a Mii, they're then allowed to place the character in a game of their choice and turn them into a playable character.

On the Nintendo DS, Miis are used in games like Personal Trainer: Walking and Tomodachi Collection.

The Miis live in a small pocket-dimension called Mii Plaza. A version of the Mii Plaza is present on the Nintendo 3DS in the application titled StreetPass Mii Plaza.

Wii Series


The Wii series of games includes the likes of Wii Sports, Wii Play, Wii Fit and Wii Music. These games' main characters happen to be Miis, and they're used in nearly every mode of each game. they're also usually seen in the background as virtual spectators (example: In Wii Play's ping pong game, they're seen around the table cheering you on. The table tennis mode in Wii Sports Resort actually had the Miis playing the game). In Nintendo Land,Mii Characters are for the first time playable in full Nintendo Costumes.

Nintendo 3DS
The Nintendo 3DS included a Mii Maker built into it. It's almost identical to its Wii counterpart though includes the ability to take a picture of someone and have the application do all of the work. Plus, there are some new Mii parts. It can detect nearby Wiis and download Miis from that system. However, it can't transfer them from the Nintendo 3DS to the Wii due to the new parts the Miis now have. It is also easier to share Miis as there is a new feature to make QR codes which can be scanned. Several games for the Nintendo 3DS have made use of the Miis in the Mii Maker, including Pilotwings Resort, AR Games, Nintendogs + Cats and more.

Wii U
Mii's are featured prominantly in the new console feature "Miiverse". The Mii Character of the user will represent them on the many community forums accesable from the "Communities" menu. When posting,the user can choose an emotion for their Mii to display (Neutral,Happy,Winking,Shock,Cringe,and Sadness). The Mii Maker returns,but is now in the form of shelves your still-standing Mii Characters will stand on (If you use a Wii Remote,point at a Mii,and press A,you can change their poses).

Mario series

 * In Mario Kart Wii, Miis are playable characters. They can also be found in various stages including Coconut Mall, Daisy Circuit, and Moonview Highway. The statues of Mario characters in the Luigi Circuit, DK Summit, Dry Dry Ruins, and the Block Plaza battle stage will be replaced by Miis if the user is controlling a Mii.
 * In Mario & Sonic series of Olympic games, Miis are playable characters & spectators.
 * In Mario Super Sluggers, Miis are playable characters.
 * Miis can be seen walking in the background of some minigames in Mario Party 8.
 * Miis are used as the file select image in Mario Party 8, Super Mario Galaxy and Super Mario Galaxy 2.
 * Miis are also used in Mario Strikers Charged as the player's user on their Save File.
 * Miis are used in Super Mario 3D Land, again as the player's user on their Save File.
 * In Mario Kart 7, Miis are once again playable characters.
 * Mii Characters are playable in Clallenge Mode in New Super Mario Bros. U. They feature the same Voices as in Mario Kart 7.

​List of First-Party Mii Compatible Games

 * Wii Sports (Wii) (Playable and Background Characters)
 * Wii Sports Resort (Wii) (Playable and Background Characters) (Some Background Characters may be imported from the Check Mii Out Channel)
 * Wii Play (Wii) (Playable and Background Characters)
 * Wii Play: Motion (Wii) (Playable and Background Characters)
 * Wii Music (Wii) (Playable and Background Characters)
 * Wii Party (Wii) (Playable and Background Characters)
 * Wii Party U (Wii U) (Playable and Background Characters)
 * Wii Fit (Wii) (Playable and Background Characters)
 * Wii Fit Plus (Wii) (Playable and Background Characters)
 * Wii Fit U (Wii U) (Playable and Background Characters)
 * Nintendo Land (Wii U) (Playable, Background, and Miiverse Characters)
 * Personal Trainer: Walking (Nintendo DS) (Playable Characters)
 * Tomodachi Collection (Nintendo DS) (Playable Characters)
 * Mario Kart Wii (Wii) (Playable and Background Characters)
 * Mario Kart 7 (Nintendo 3DS) (Playable and Background Characters)
 * Mario Super Sluggers (Wii) (Playable Characters)
 * Mario Party 8 (Wii) (Playable and Background Characters)
 * Mario Tennis Open (Nintendo 3DS) (Playable and StreetPass Characters)
 * Mario Strikers Charged (Wii) (File Select Characters)
 * Super Mario 3D Land (Nintendo 3DS) (File Select and StreetPass Characters)
 * New Super Mario Bros. 2 (Nintendo 3DS) (StreetPass Characters)
 * New Super Mario Bros. U (Wii U) (Playable,Background,and Miiverse Characters)
 * Brain Age: Concentration Training (Nintendo 3DS) (File Select Characters) (Default Non-Mii Icons can be used instead,labeled "Me","Brother","Sister","Mom",etc.)
 * Fortune Street (Wii) (Playable and Background Characters)
 * Big Brain Academy: Wii Degree (Wii) (Playable,File Select,and Background Characters) (Mii Characters from your Wii Friends can appear as Background Characters)
 * Super Smash Bros. Brawl (Wii) (Choosable Icons on your Friend Roster)
 * Kid Icarus: Uprising (Nintendo 3DS) (File Select and StreetPass Characters)
 * Animal Crossing: City Folk (Wii) (Players can buy a "Mii Mask",which lets them use their Mii as their Character's Face)
 * Animal Crossing: New Leaf (Nintendo 3DS) (Mii Mask)
 * My Pokémon Ranch (WiiWare) (Mii Characters can live on your Ranch, and interact with your Pokémon)
 * Pokémon Rumble Blast (Nintendo 3DS) (Background and StreetPass Characters)

Trivia

 * Miis are based off of the idea of customizable characters, through the idea of Recycled Characters. Whereas they all have the same basic base, but are customizable by the player.