Every time you win Usopp's Pirates' Challenge, you will unlock six pieces of art in the Art Gallery. There are 198 pieces of art to unlock, so getting all of it requires you to beat Usopp's Challenge 33 times. Take note that you must have all of the characters in order to get all of the art.
If Zoro gets set on fire quickly attack the opponent with Oni Giri. Zoro should say "Flaming Oni Giri" And if it connects the opponent will take extra damage and (might) go on fire.
Buggy, Don Krieg, Kuro, Arlong, and Chaser:
Beat Story mode with Luffy, Zolo, Nami, Usopp, and Sanji.
Ms. Sunday: Beat Story Mode with Buggy, Don Krieg, Kuro, Arlong, and Chaser.
Chopper: Beat Story Mode with Luffy, Nami, or Sanji in Hard Mode after you unlock Ms. Sunday.
Shanks: Beat Story Mode with Luffy on Very Hard after you unlock Chopper.
Mihawk: Beat Story Mode with Zolo on Very Hard after you unlock Shanks.
Chase- Destroy all pillars in Training Mode with three or more characters.
Flee- Destroy all pillars in Training Mode with one or more characters.
Guard Crash- Destroy all pillars in Training Mode with nine or more characters.
Item- Destroy all pillars in Training Mode with five or more characters.
Jump- Destroy all pillars in Training Mode with seven or more characters.
Super Attack- Destroy all pillars in Training Mode with twelve or more characters.
Support Attack- Destroy all pillars in Training Mode with one or more characters.
Ultimate Secret Attack- Destroy all pillars in Training Mode with thirteen or more characters.
Break the eight pillars in training mode with 14 different characters.
To unlock this difficulty level, you must complete story mode with the difficulty set on hard ten or more times.
Mr. 0 Crocodile: Beat any mode on story mode with Ms. Sunday and hold L and press Down,A,<,Down,Y,A,X,B,Up,X,R,<,Y,>,B,R.
(Can only be unlocked after you unlock Mr. 2 Bon Clay)
Alabasta Kingdom: Beat story mode with Mr. 0 Crocodile.
Sound Test: Unlock Mr. 0 Crocodile
On the title screen, press these codes to get two extra costumes for Luffy, Zolo, Nami, Usopp, Sanji, and Chopper.
[Hold L] up, A, up, A, B, A, A
[Hold R] up, X, up, X, B, A, A, up
[Hold L] down, A, down, A, B, A, Y
[Hold R] down, X, down, X, B, A, A, Y
[Hold L] left, A, left, A, B, A, Y
[Hold R] left, X, left, X, Y, Y, B, down
[Hold L] right, A, right, A, B, A, Y
[Hold R] right, X, right, X, A, Y, B, X
[Hold L] up, A, down, A, B, A, X
[Hold R] up, X, down, X, Y, B, Y, X
[Hold L] Y, left, right, A, up, A, down
[Hold R] left, A, right, X, Y, left, right, B
First, here's how to get Mr. 2 Bon Clay:
Characters one through fourteen must be unlocked. That's the default characters plus four hidden characters, including Ms. Sunday, Tony Tony Chopper, Red Haired Shanks, and Hawkeye Mihawk. Then, use Sanji in Story Mode (Any difficulty) and enter this secret command while the end credits are rolling:
[Hold L]+ A,A,X,A,<,A,X,B,A,X,Y,X,A,R,R,<
Next, here's how to unlock Mr. 0 Crocodile:
Characters one through fifteen must be unlocked. Then, use Ms. Sunday in Story Mode (any difficulty) and enter ths command at the ending credits:
[Hold L]+ Down,A,<,Down,Y,A,X,B,Up,X,R,<,Y,>,B,R
To do these Codes you must Beat Story Mode with any Character or any difficuly Setting
Buggy- Hold L and Press A Right Right Right Right Right Right A A A X X X
Chaser- Hold L Press B B X X A A Down Down Up Up B B B
Kuro- Hold L and Press X X X X Left Left Right Right Right Y Y Y Y
Don Krieg- Hold L and Press Down Down B B B B B Right Right A A A A
Arlong- Hold L Oress Down Down X X A A Down Down Down Down Down Left Down
Ms. Sunday-Hold R and Press Up Y Up A Down X Up B Right B Left A Right Y Down L
Chopper- Hold R and Press B Down L Up A Right X Down X Down Y Right A Left L X
Shanks- Hold R Press Right B Left A Left L Right B Right L Down A Left B Right Y
Mihawk- Hold R and Press Right L Up B Up L Right Y Left X Left A Down A Left L