At the title screen, press Triangle, Left, Right, Left, Triangle.
Bonus characters
At the title screen, press Right, Right, Triangle, Left, Left.
Tarot option
At the title screen, press Up, Triangle, Down, Triangle, Up.
Talk Demo option
First enable both Bonus characters and Tarot option. Then at the title screen, press Square, Up, Left, Down, Right, Up, Square, Down, Left, Up, Right, Down, Square.