Certain things can be unlocked once you finish the game.
Unlockable How to Unlock
Boss battle finish the game once.
Gaara as support character finish the game once.
Kakashi as support character finish the game once.
shuriken pattern finish the game once.
Contributed By: Meteorites.
Chakra Refill Boost
During the Loading screen if allocated enough time to move the right thumbstick enough in a circle. A Blue Chakra Ball will pop-out and if you notice your unfilled Stamina / Chakra Bar. It will refill a little about 25% worth everytime you do this. Between Loading screens with the Konoha Symbol in the lower right corner