Earn an "A" rank in Mercenaries mode with the indicated character to unlock the corresponding costume.

Pirate Leon: Earn an "A" rank as Leon.
Puffy Jacket Jake: Earn an "A" rank as Jake.
R.P.D. Helena: Earn an "A" rank as Helena.
Racer Piers: Earn an "A" rank as Piers.
Samurai Chris: Earn an "A" rank as Chris.
School Girl Sherry: Earn an "A" rank as Sherry.
White Dress Ada: Earn an "A" rank as Ada.