Pokemon Scarlet and Violet: How to claim new DLC uniform sets in-game

At the tail-end of the recent Pokemon Day announcement, some big news was dropped for Pokemon Scarlet and Violet.

Pokémon Scarlet and Violet Hidden Treasure of Area Zero DLC

Pokemon Scarlet and The Hidden Treasure of Area Zero DLC Bundle

The Hidden Treasure of Area Zero — Pokémon Scarlet and Pokémon

Pokémon Scarlet & Violet - All Uniform Set List Including DLC

How To Unlock New Teal Mask DLC Outfits in Pokémon Scarlet

Pokémon Scarlet Bundle Nintendo Switch, Nintendo Switch – OLED

Are the new School Uniform sets preorder bonus only, or do you get

Pokémon Scarlet and Pokémon Violet

Pokemon Scarlet Bundle - Nintendo Switch (digital) : Target

Pokémon™ Scarlet/Pokémon™ Violet Expansion Pass: The Hidden