Miis strangely don't get much attention when it comes to fanfiction.
"What are you doing?" A Mii asked another Mii on the Mii Channel.
"I'm tired of just being used to fill in the gap; I'm heading out." The Mii said, placing on a helmet and taking off.
"Well good luck."
So the helmet wearing Mii went off for a strange journey: where it decided to go was beyond anyone's thought.