Invincibility (Japanese version)
At the title screen, quickly press [Triangle(2), Left, Right, Square(2), Select, L1, L2, R1, R2] three times within five seconds. If you entered the code correctly, the background color will turn blue.
All items (Japanese version)
When the conception sequence begins at the title screen, press Circle(6), sweep the D-pad in a clockwise Full-Circle three times, and press Triangle, Square(2),Triangle, X, Start.