Hidden Room in Ancient Ruins
To find the hidden room, go to the pit near the beginning of the level. Stand at its edge and press R1 + R2. A piece of ground will materialize. Jump on to it, and you will see a number of pillars. Go either right or left and jump between the pillars to find the secret room.

Duplicate Item
First go to object untity at the start menu. Next, select auction and load two or four of your characters and then choose the item you want to sell. when you sell to the other character then save it.

Note: Don't save to your character who lose its item and click this L1+L2+R1+R2+select+start. And you go back at the start menu. when you begin the game you will have the same item as the owener of your character