Ash Ketchum meets Pikachu and begins his Pokémon adventure.
Instead of looking forward to his birthday the next day, Ash Ketchum of Pallet Town spends his night worrying about which Pokémon he will receive from Professor Oak. Once a boy turns 10, he is allowed to receive his first Pokémon and begin his very own Pokémon adventure.
Ash wakes up late the next day and races to Professor Oak's house. Upon arriving, he runs into his rival Gary, who has already received his first Pokémon. Professor Oak informs Ash that his Bulbasaur, Charmander, and Squirtle, the three Pokémon normally given to starting trainers, have already been claimed. Ash insists that he will take any Pokémon, and despite Oak's warnings, is introduced to Pikachu. The rebellious Pokémon shocks Ash as they embrace.
Together, Pikachu and Ash begin their journey, though problems arise as Pikachu refuses to return to a Poké Ball or fight wild Pokémon. Ash tries to catch a wild Pokémon by himself, but accidentally upsets a Spearow which he mistakes for a Pidgey. The wild Spearow begins to attack Ash and Pikachu. Pikachu shocks the Spearow, but in doing so alerts the whole flock to their presence.
Ash grabs Pikachu and takes flight from the pursuing flock of Spearow, eventually diving off the top of a waterfall. A young girl (eventually known to be Misty) fishes the two out of a lake, and tells Ash to take the Pikachu to a Pokémon Center in order to heal it. The Spearow resume their chase, and Ash "borrows" Misty's bike to escape.
The Spearow flock eventually catches up to Ash and Pikachu, and Ash pleads the injured Pikachu to take a shelter in a Poké Ball so that he can fight the Spearrow by himself. Pikachu recognizes the huge risk that Ash is taking, and performs a powerful electrical attack to drive the Spearow away.
With a bond of friendship and trust now formed, Ash and Pikachu continue on towards the nearby city as a mysterious bird flies overhead.