The Mii Parade is a feature on the Mii Channel.
A Wii user can send their Miis to the Mii parade and then, simply watch the Miis walk across a location similar to the Mii Plaza together. The user can also make their Miis run across the location together.
Unfortunately, sending a Mii to the Mii parade will erase all data for the Mii (excluding how the Mii looks and its name). The data that gets erased is the Miis birthday, creator, and any of the Miis saved files for games. It will also disable using the Mii in any of the games as well.
Miis that are sent to the Mii parade can be also brought back to the Mii Plaza.
There is a certain option on the Mii Parade screen known as "Travel Settings". When a player turns on traveling mode, Miis that are set on "Mingle", created by other Wii users will be able to gather into the players Mii Parade at random times and stay their, unless if the player erases them. Miis that aren't mingle won't appear in other people's Mii Parades. Also when playing on Wi-Fi mode for certain games that feature Miis, the Mii that represents a Wi-Fi user will be sent to the player's Mii parade if the Mii is mingle