Pikachu is the player’s fixed companion in Pokémon Yellow Version.
Released in Japan in 1998, Pokémon Yellow is an enhanced version of the first-generation games. Its presentation was influenced by the Pokémon anime, so the player begins with Pikachu rather than choosing Bulbasaur, Charmander, or Squirtle as in Red and Green.
Pikachu follows the player outside its Poké Ball and reacts to the player through an affection system. The game also gives the player opportunities to obtain the three traditional Kanto starter Pokémon, allowing one adventure to include Pikachu plus the familiar trio.
This setup is different from the original Red, Green, and Blue games, where the player chooses one of three starters at Professor Oak’s laboratory. Pokémon Yellow is also distinct from the anime: it borrows characters and ideas from the television series but remains a separate game with its own rules, maps, and progression.