Unlock Crocodile
How to: First you need characters 1-15 the beat story mode with all of the 15 characters on all difficulty modes. Then win the game again on very hard mode with Luffy. When the credits of done there will be no image of crocodile being unlocked. Go to story mode, at the character select screen you will see crocodile pick him and beat story mode. At the end of the credits it should show his image of him being unlocked. Now he is then free to use in any game mode.

BGM Test
How to unlock: Win the Event Battle with all 19 characters.

Chopper's 4th Costume
How to: From the Start Screen, hold down R and enter LEFT, A, RIGHT, X, Y, LEFT, RIGHT, B.

Unlockable: Groggy Ring
Beat 3 events in the Davy Back Fight, and win the Davy Back Fight 3 times.

Unlockable: Donut Race
Beat the Davy Back Fight 10 times.

Unlockable: Crash Rush Boxer
Beat the Davy Back Fight 18 times.

Unlockable
Breaking Krieg's Armor-Beat the Davy Back Fight 29 times
Unlockable: Crash Rush Boxer-Beat the Davy Back Fight 18 times.
Unlockable: Donut Race-Beat the Davy Back Fight 10 times.
Unlockable: Groggy Ring-Beat 3 events in the Davy Back Fight, and win the Davy Back Fight 3 times .

Unlockable: Sanji & Zoro voice (Announcing)-You must win 33 times and play Davy Back Fight once.
Unlockable: Snow-You must win the Davy Back Fight 26 times.
Unlockable: The Fix sign-You must win the Davy Back Fight 34 times.
Unlockable: Different System Voices-You must play the Usopp's Pirates' Challenge and beat all 3 games to unlock anew System Voice.

Unlockable: BGM Test
Win the Event Battle with all 19 characters.

Unlockable: Breaking Krieg's Armor
Beat the Davy Back Fight 29 times

Unlock Characters
Chaser, Buggy, Don Krieg, Saw Tooth Arlong, Captain Kuro: Clear story mode with all five "Straw Hat" pirates.

Mrs Sunday, Tony Tony Chopper: Clear story mode with all "Straw Hat" pirates as well as Chaser, Buggy, Captian Kuro, and Saw Tooth.

Hawk Eye Mihawk: Unlock Shanks and clear Story Mode on Very Hard with Zolo. Additionally, get struck by Shank's level 2 special move while beating Shanks with Zolo's special at level two. (Alternate: You must have have unlocked characters 1-13 then beat very hard with zolo and you unlock him. from c dog).

Red Hair Shanks: Clear Story Mode on Very Hard with Luffy.
Mr. 2 Bon Clay: Unlock characters 1-14 first, including the 4 hidden characters (Ms. Sunday, Tony Tony Chopper, Red Haired Shanks and Hawk-Eye Mihawk). Next play as Sanji in Story mode on any difficulty. Enter the following command as the end credits run.
Hold L and press A, A, X, A, LEFT, A, X, B, A, X , Y, X, A, R, R, LEFT

Crocodile: Unlock characters 1-15 1st (Mr. 2 Bon Clay, Ms. Sunday, Tony Tony Chopper, Red Haired Shanks and Hawk-Eye Mihawk). Next play as Ms. Sunday in Story mode on any difficutly. Enter the following command as the end credits run. Hold L and press DOWN, A, LEFT, DOWN, Y, A, X, B, UP, X, R, LEFT, Y, RIGHT, B, R.