At the start of Pokémon Go, players are presented with option of choosing one of the three classic starter Pokémon from Pokémon Redand Blue: Bulbasaur, Charmander, and Squirtle. Sadly it doesn’t appear that Pikachu available to select as your first Pokémon.
It turns out that with a bit of knowhow and patience, Pikachu can in fact be your first partner in your Pokémon Go journey, and you can play the game in true Pokémon Yellow style.
When you start playing, Professor Willow prompts you to choose one of the three presented starters, who all pop up on the in-game map. If you don’t initiate battle with any of them, though, and walk away from the area, they should all disappear and then respawn to wherever you moved to. If you do this four times, the next time the starters pop up again, they should have Pikachu with them.
Bear in mind that this method might take some time to work for you: It took our team 30 minutes until it happened for them.