Guide to unlock all Mita Clothes in MiSide.
MiSide: How to unlock Mita Clothes
School uniform
Inspect it on the wardrobe at the “Together at last” chapter.
Vampire costume
Main game: Interact with pumpkins in the kitchen at the “She just wants to sleep” chapter.
Demo version: Complete the demo.
Christmas costume
Beat Mita 2 times out of 2 in «Penguin Piles» game on console in «Things get weird» chapter.
What about second icon in the Main clothes item?
It’s a slot for custom clothes. You can change textures for it and (almost) all Mitas will wear it. Unfortunately it’s not a completed feature yet, so do it at your own risk and don’t complain.
You can find textures to change at: %GameFolder%/Data/Custom/New (Original).