Clear various mission or challenges to unlock this costumes.
Costume
How to unlock
Booster Unit
Clear the Mission "...".
Lost All
Clear the Mission "...".
Schoolgirl
Obtaib 99,999 damage in the mission "Nana's Whimsical Test".
Defender Glitch
Use Defender Skill and then hold X to keep blocking. And when your life bar gets to 0 and the Defender is still active, Keep on Blocking so that you can't die. Because when you life bar gets to 0 the Atk/Def/Regen Boosts will stay stuck as it is. But even though the Regenerate/+ is still active while blocking with 0 HP, you still won't recover HP This is pretty useful at XNFE's Extra Mission - Prelude: Suicide TV.