57e47233_and_Secrets_for_3DS___GameFAQs__How_to_Unlock
[Unlockable] Speed Freak [How to Unlock] 
Finish each round in Arcade Mode on Medium or higher in 20 seconds or less. Too easy.
Super Street Fighter IV: 3D Edition Cheats, Codes, and Secrets for 3DS - GameFAQs