Just like in previous Tag Force games for the PSP, the code that unlocks the Midday Constellation Booster Pack in the store. Go to the store and talk to the cashier, when she asks you, if you would like to shop around, say yes. When you come up to the booster pack menu, you enter the cheat there.

Code	Effect
Up, Up, Down, Down, Left, Right, Left, Right, X, O	Unlocks the Midday Constellation Booster Pack in the store.