Change Custom 1 & 2
At the title screen menu hold L1, R1, Select and triangle for Custom 1
At the title screen menu hold L1, R1, Select and Square for Custom 2
Extra Mode
Complete the game with an "A". This will unlock an Extra Mode menu, which contains modes such as "Time Attack" and "Score Attack" mini-games.
Sound Test
Press Left, Circle, Down, Triangle, RIght, Square, Up, X, L1, R2, L2, R1 + Start at the title screen. Sound Test should appear under option Option Mode.
Unlimited Power Spell
Hold L1 + L2 + R1 + R2 at the main menu then start a game.
School Uniform
Hold L1 + R2 + Select + Triangle at the title screen and start a game