Airblade

Unlock J. J. Sawyer
Finish the game and reach an "S" rank in every level

Unlock Naomi
Finish the Downtown level and reach a "B" rank

Unlock Oscar
Finish the game and reach an "A" rank in every level

Unlock The Insider
Finish the Storage level and reach a "B" rank

Stunt attack mode
Finish story mode once

Unlock Ethan 3rd clothes:
Finish stunt attack mode

Unlock Kat 3rd clothes:
Finish score attack mode an reach high scores in every level