Unlock Secret Characters
In Story mode using any default character complete his or her story to unlock a secret character and then complete the story with the character you have just unlocked to unlock another secret character.

Unlock Neji Hyuuga:
Complete Story mode with any default character.

Unlock Hinata Hyuuga:
Complete Story mode with Neji Hyuuga.

Unlock Haku:
Complete Story mode with Hinata Hyuuga.

Unlock Zabuza Momochi:
Complete Story mode with Haku.

Unlock Gaara:
Complete Story mode with Zabuza Momochi.

Unlock Orochimaru:
Complete Story mode with Garaa.

Unlock Alternate Costumes:
At the Selection screen when choosing a character hold L1 + R1.

Unlock Bonus 'S' Rank Missions:
Complete 'S' rank Mission 2, 'Icha Icha Paradise' to unlock Mission 11. To unlock Mission 12 complete ALL non-'S' rank missions (Hokage rank).