Which Pokémon game first made Pikachu the player’s permanent companion?

Pokémon Yellow first made Pikachu the player’s permanent companion.

Released in Japan on September 12, 1998, Pokémon Yellow is an enhanced version of the first-generation games. It was designed to reflect the popular anime more closely, so the player begins with Pikachu rather than choosing Bulbasaur, Charmander, or Squirtle.

Pikachu follows the player outside its Poké Ball and reacts to the player throughout the adventure. The game also makes it possible to obtain all three original starter Pokémon during the story, echoing Ash’s anime journey while preserving the basic Kanto setting.

Pokémon Yellow is not the first Pokémon game and does not replace Red and Blue in release order. It was a later enhanced edition, released after the Japanese versions of Red, Green, and Blue and before its international editions in 1999.