In "Pokémon the Movie: I Choose You!", Professor Oak operates as a Pokémon researcher in Pallet Town, managing starter distributions for new trainers. When Ash Ketchum starts his journey, Oak broadcasts the traditional starter options—Bulbasaur, Charmander, and Squirtle—to other trainers. Ash arrives late and misses his chance to select one. Oak instead supplies him with a Pikachu, openly cautioning about its volatile nature and inexperience for beginners. Despite the warning, Oak permits Ash to take Pikachu, displaying flexibility and faith in the trainer’s potential.

Portrayed as considerate and supportive, Oak equips Ash with Poké Balls and advises patience and understanding toward Pikachu. This depiction contrasts with earlier versions, showing him as consistently encouraging from the beginning. After Ash leaves Pallet Town, Oak’s active role recedes; he neither joins Ash’s quest for the Legendary Ho-Oh nor engages with companions Verity and Sorrel.

The film presents an alternate continuity distinct from the main anime. Oak’s involvement centers on the introduction, launching Ash’s journey from his laboratory. His choice to entrust Pikachu to Ash forms the plot’s cornerstone.