Unlock 2 Player Mode:
Both players hold R1 + R2 + L1 + L2 at the Title screen, then player 2 press Start. A sound confirms that the code has been entered correctly.

Unlock Arena Mode:
From the Menu screen, select Special and keep the cursor on the word Exit and enter Square, L1, R2, Square, Left, L1, L2, L3, Right, Triangle.

Unlock Onimusha Arena:
Finish the game on Normal mode and it will appear in the Special menu on the Title screen.

Unlock Street Fighter Costumes:

From the Menu screen select Special and keep the cursor on the word Exit and enter the following codes to unlock the corresponding costume:

Unlock Tenkai Kens Costume:
L3, L3, R3, R3, R3, Left, R2, L1, Square, Right

Unlock Ohatsu Chun-Lis Costume:
R3, Right, L2, Left, Left, R3, L1, R1, Right, R3

Unlock Jubei Cammys Costume:
L2, L2, Right, Right, L3, Triangle, Left, L1, L2, Square

Unlock Roberto Guiles Costume:
R2, L2, Left, L1, Left, Right, R3, Square, Square, Triangle

Unlock Soki Ryus Costume:
Left, Triangle, R2, R3, Square, R1, R1, Right, Left, L2

PAL Version - Unlock Street Fighter Costumes

Unlock Robertos Guile Costume:
Left, R3, Right, Left, R3, L1, L2, R1, Right, R3

Unlock Sokis Ryu Costume:
R1, Square, R1, Left, Triangle, R2, R3, Right, Left, L2

Unlock Jubeis Cammy Costume:
Square, L1, R1, R3, Left, Triangle, R1, Square, Triangle, L2

Unlock Ohatsus Chun-Li Costume:
L2, L2, L3, Triangle, Left, Right, Right, L1, L2, Square

Unlock Tenkais Ken Costume:
L2, R2, Left, Right, R3, Left, L1, Square, Square, Triangle

Japanese Version - Unlock Street Fighter Costumes

First Set of Secret Costumes:
Complete the Test of Valor for all

Second Set of Secret Costumes:
Complete the Test of Valor with Gold Ranking for all

Third Set of Clothing:
Finish the game with all 10 Oni Charms.

Unlock Silly Weapons:

From the Menu screen, select Special and keep the cursor on the word exit and enter the following codes to unlock the corresponding. The weapons will be added to your inventory when you start or load your next game.

Unlock a Piggy Bank for Ohatsu:
Right, Triangle, Left, L3, L1, Triangle, Square, R2, Square, R2

Unlock Boxing Gloves for Roberto:
Triangle, R3, Triangle, Right, R1, L3, Triangle, L1, Right, L3

Unlock a Steel Pipe for Soki:
L2, Square, Triangle, R1, R1, R3, Left, Square, L1, Triangle

Unlock a Microphone Stand for Tenkai:
R2, R3, Square, Left, Left, Right, L2, Left, R2, Left

Unlock a Racquet for Jubei:
L1, R1, Right, L2, Triangle, Right, L1, Right, L3, R1