Successfully complete the indicated task to unlock the corresponding costume:

Academia Jersey: Unlock all GX anime characters in Tag Duel mode.
Blue Uniform: Unlock all GX anime characters in Single Duel mode.
E Hero Neos or Cyber Tutu: Get a 100% card collection.
Elf Swordsman or Dark Magician Girl: Successfully complete the World Of Order.
Kaibaman Coat or Harpy Lady Costume: Win five times with 70 Single Duel opponents.
Kimono: Successfully complete all Seal Stone challenges.
King Coat or Queen Coat: Get an 85% card collection.
Moonlight or Clerk Uniform: Win the Tag Tournament on the Easy, Medium, and Hard difficulty setting.
Night Light or ?: Win five times with 20 Tag Team opponents.
Stuffy Collared Shirt (Blazer): Unlock all original anime characters in Single Duel mode.
T-shirt: Have 200 total duels.
White Jacket or Gothic: Successfully complete the World Of Civilization.
Yellow Uniform: Have 400 total duels.