Unlockables
Unlockable costumes in the game

Once you complete the requirements for the clothing, they're automatically thrown in your closet, in all your safehouses.

Final Cut (New Coventry) houses all of the punk-esque items in the game. Worn In (Bullworth Town) houses more beachy, sporty, and middle classy type clothing. Aquaberry in Bullworth Vale houses all the upper crust type clothing, although until Chapter 3 the only clothes you can get in there are the Aquaberry Sweater and Vest.
Unlockable              How to Unlock
Black Ninja Outfit      Fill up your yearbook completely.
Black Skate Shoes       Travel at least 50.00km on foot
BMX Champion            Complete one of the bike races.
Boxing Outfit           Beat either 'Boxing Challenge' or 'Prep Challenge' in Chapter 2.
Crash Helmet            Place 1st in the Kart Race at the Carnival
Dunce Hat               Go to the boys locker room in the gym and turn on all the showers.
Edna Mask               Destroy 19/19 Tombstones during Halloween
Fast Food               Complete the Burger Joint errand found in Bullworth Vale.
Firefighter's Helmet    Pull the Fire Alarm 20 times
Gnome Costume           Smash all garden gnomes.
Gold Suit               Buy all clothing in the game.
Green Ninja Outfit      Hit stuff with projectiles (eggs, etc.) 1000 times.
Grotto Master           Collect all G&G cards.
Jimmy's Skeleton Halloween costume	Beating the mission 'The Candidate' will open up the mission 'Halloween' which unlocks the costume.
Orderly Uniform         Complete 'Finding Johnny Vincent' in Chapter 5.
Pirate Hat              Beat up pirate on island near Beach House.
Prison Uniform          Beat all the detention mini games at least once.
Pumpkin Head            Destroy all the 27 pumpkins during "Halloween Event" They are around the school and inside the main building
Red Ninja Outfit        During Halloween (must be done during Halloween) at Bullworth Academy, complete the Big Prank task
School Mascot           Beat 'Nice Outfit' in Chapter 4.
Tiny Swimsuit           At the Beach House location, find the Preppie with a blue mission on the beach and beat his swimming time
Wrestling Uniform       Beat Gym 1.