Mii™ characters are cute caricatures that you create to use as players in Wii Sports and other specially designed Wii games. In Wii Sports, they store your high scores and skill levels.
Create your own Mii characters in the Mii Channel, then store them on your Wii console—or load them onto your Wii Remote and take them over to a friend’s house to use on their Wii console. Get everyone in the family to create a Mii for their own Wii Remote!

Go to the Mii Channel on your Wii Menu.

Select the New Mii icon.

Start creating! Use the icons to add features to your Mii—like a smile, eye color, funky hairdo, and more.
The Check Mii Out Channel is the place for Mii characters to mingle! You can show off your Mii creations and download ones that others have created to play in Wii Sports. You can also participate in Mii contests by creating and judging Mii characters for a specific contest theme. Download it for FREE from the Wii Shop Channel.
First make sure that your Wii console is connected to the Internet. Then, head to the Wii Shop Channel on your Wii Menu.
Once inside of the Wii Shop Channel, head to the "Wii Channels" section. Find the Check Mii Out Channel, and download it.
Head back to your Wii Menu, and you will now see the Check Mii Out Channel there. Click on the channel, and get ready to have some fun!