To unlock every character in the game automatically (except for Hyuuga Hanabi and 4th Hokage Yondaime), do the following. At the game's main menu, hold down R1 and R2 together, and press Square, Triangle, Square, Triangle. Then, press and hold down together L1 and L2, pressing Right, Up, Right, Up. Finally, press L3 and R3 (analog sticks) together. If done correctly, a sound will chime, and the characters will be unlocked for use.