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Throughout the game, you have to collect many important items that can be stored in the toolbox:

Item	Description
Ball	This is Pikachu's beach ball; Pikachu gives it to you early in the game.
Cupcake	This is a treat for Pikachu.
Fishing Hook	This is used for fishing.
Harmonica	This can be given to Pikachu for him to play different tunes.
Trumpet	Similar to the Harmonica.
Lucky Hook	This hook is used to catch rare Pokémon.
Megaphone	This is used to talk to Pikachu when it runs away. It can only fire sound in a straight line, and does it too loudly for normal use.
PokéHelper	This device is used to talk to Pikachu.
Watering Can	This is used to water Oddish and Gloom in the different parts of Springleaf Field. It can hold 5 servings.
Watering Pail	This is used to water Oddish and Gloom in the different parts of Springleaf Field. It can hold 30 servings.
Flying Acorn	Most likely the last item to be purchased from Abra's shop. Its availability is dependent on the amount of days spent with Pikachu. It is a brown acorn with three leaves sprouting from the top. The item works very similar to the Frisbee but will cut off fruit from trees with which it comes into contact.