All characters:
Press Up, Down(2), Square, Circle,
Down, Triangle, R3 + L3 at the main
menu.

Gallery:
Successfully complete the game as any character.

Hard difficulty:
Successfully complete Single player mode under the
normal difficulty setting.

Very Hard difficulty:
Successfully complete Single player mode under the
hard difficulty setting.

Time Attack mode:
Successfully complete Single player mode under the
very hard difficulty setting.


Hint: Unlocking characters::
Gain money by doing missions, then go to the slot machine.
Get three of the Shonen Jump signs (a head with a flag behind).
You will then be taken to the bonus slot machine mini-game. Get
three of the heads that have a "?" on them to unlock
a character.

The following characters can be unlocked by defeating them in
Single player mode, then playing the slot machine until they are
won:


Buu
Cell
Frieza
Gaara
Majin Buu
Nami
Rock Lee
Trunks
Ussop