Miis are the avatar on consoles like the Wii.
The Miis are avatars used in the Wii, Nintendo DS, Nintendo 3DS, Wii U and Nintendo Switch titles. They come with more than 10,000+ possible combos to make.
Miis took a long path to be finalized.
Make Someone You Know project's start
The Miis first originated on the Famicon. After the Famicon Disk System was released in Japan, Miyamoto had the idea of a game to make faces. Nicknamed as "Make Someone You Know project" game, it also came with a "Scenario Disk" to use them. Reviews were critical, as people didn't think it was a game, and was more of an art tool.
Mario Artist: Talent Studio
Then, they travelled to the Nintendo 64 in 1999, at the release of the N64 Disc Drive, Miyamoto had the idea to make sequels to Mario Paint, a game for the SNES, known as Mario Artist. There were 3 games released - Mario Artist: Paint Studio, Mario Artist: Polygon Studio and Mario Artist: Talent Studio. Talent Studio was based off Make Someone You Know, and just like it, you could make faces and insert them into scenarios. Mario Artist was released, but the game and the N64 Disc Drive alone had low sales. Still, employees didn't think it was much of a game.
The GameCube and GameBoy Advance were now getting 3 new accessories - the GameBoy Pak, the e-Readers, and the i-Cam. Miyamoto's idea was getting new life - a game where you can have your face on a GameCube game. People doubted it could be a full-on game, so it was also scrapped.
Hope for the Best
In 2005 to 2006, the Wii was being planned. Miyamoto got his last hope of a personalised experience for characters. The reason they failed is that they were a bit too complicated and needed too much accesories. Around this time, Miis were more like Kokeshi dolls, and would be simple. At another part of Nintendo, other devs were designing Miis on a DS game, but, they thought the parts needed to be resizable and repositionable, to make Miis of other people like Sakamoto. Sakamoto passed it onto Iwata, who then passed it onto Miyamoto who loved the idea, and joined Sakamoto's side, Nintendo EAD. After a few bits of tweaking, the Mii Channel and the Miis alone were ready.
Games using Miis