Miis are customizable characters that were debuted alongside the Wii via the Mii Channel, the Nintendo 3DS, the Wii U via the Mii Maker, the Mii Maker via Nintendo Switch, and on iOS and Android devices through the Miitomo app. 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.
The Miis live in a small pocket-dimension called Mii Plaza. A new version of the Mii Plaza is present on the Nintendo 3DS in the application titled StreetPass Mii Plaza, where they are the main characters of Puzzle Swap and Flower Town, and the main protagonists of Find Mii, Mii Force, and Monster Manor.
- Main article: List of games with Miis
Miis first appeared on the Wii console in the Mii channel, where Mii creators could choose what the Mii looks like and then save the Mii's look. They also appear in the Wii series, which includes Wii Sports, Wii Play, Wii Fit and Wii Music. The main characters of these games happen to be Miis, and they're used in nearly every mode of each game. They're also often seen in the background as virtual spectators. For example, in Wii Play's ping pong game, Miis can be seen around the table cheering you on. The table tennis mode in Wii Sports Resort actually had the Miis playing the game.
The Nintendo 3DS includes a Mii Maker application built into it. It's almost identical to its Wii counterpart, though it does include new customization options, the ability to take a picture of someone, and have the application auto-generate a Mii to match. Additionally, there are some new Mii parts. The 3DS can connect to a nearby Wii console and download Miis from that system. However, Miis cannot be transferred from the Nintendo 3DS to the Wii due to the new part options the Miis on 3DS have. The 3DS makes it easy to share Miis with a feature to make and scan Mii QR codes which can be shared as one pleases. Several games for the Nintendo 3DS have made use of Miis, including Pilotwings Resort, AR Games, Nintendogs + Cats, Super Smash Bros. for Nintendo 3DS, and more.
Miis on Wii U carry over the same customization options as on 3DS. Miis were featured prominently in the now-defunct "Miiverse" social network service on Wii U. The Mii character of the user represented them on the many community forums on the service. When posting, the user could choose an emotion for their Mii to display (neutral, happy, winking, surprised, frustrated, or sad). The Mii Maker made a return, featuring shelves for the saved Mii characters will stand on. Using a Wii Remote, you can point at a Mii and press A to change their poses. In Nintendo Land, Mii characters are for the first time playable in full Nintendo costumes.
Miis once again return for Nintendo Switch. However, there are several changes. While Miis can still be used for the player's avatar, icons of various Nintendo characters are available to use as well, making Miis a more optional feature for the Switch system. Mii customization options remain largely the same from 3DS and Wii U with a few additions. Hair color options now span a wide variety of color shades (100 in all), rather than only natural hair colors like blond, brown, black, and gray. Another new feature is that Miis can have a few new glasses designs. Their glasses can also be changed to a variety of colors (with the same color options as for hair). The Look-Alike option of creating a Mii, last seen on the Wii, also makes a return. On the Switch, Miis may be transferred to and from amiibo, either between Switch consoles or from a 3DS or Wii U. Unfortunately, unlike the Wii U, which supports over 3000 Miis saved on one console, the Mii storage limit on Switch was reduced back to 100.
- 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, and are also playable in the Extras Zone minigames of 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.
- In Mario Sports Mix Miis are playable characters.
- 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 Challenge Mode, Boost Mode, and Coin Rush in New Super Mario Bros. U. They feature the same voices as in Mario Kart 7.
- In Mario Kart 8 and Mario Kart 8 Deluxe, Miis are once again playable characters since Mario Kart 7. They gained their new voices, racing helmets and suits, and amiibo racing suits and helmets (After you tap an amiibo figure to unlock).
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 Sports Club (Wii U) (Playable and Background Characters)
- 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)
- Friend Collection (Tomodachi Collection) (Nintendo DS) (Playable Characters)
- Tomodachi Life (Nintendo 3DS) (Playable Characters)
- Miitopia (Nintendo 3DS) (Playable and Background Characters)
- Mario Kart Wii (Wii) (Playable and Background Characters)
- Mario Kart 7 (Nintendo 3DS) (Playable and Background Characters)
- Mario Kart 8 (Wii U) (Playable 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 Golf: World Tour (Nintendo 3DS) (Playable 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)
- Super Smash Bros. for Nintendo 3DS/Wii U (Nintendo 3DS / Wii U) (Playable Characters in 3 variants: Brawler, Swordfighter, and Gunner, Background Characters in certain stages, Fighting Mii Team)
- Main article: Mii/gallery
- 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.