Young Samuel Oak, known as Sam (Yukinari in Japanese), appears as a child in "Pokémon 4Ever", originating from 40 years prior to Ash Ketchum’s era. During his youth, Sam visits a museum where an Omanyte fossil exhibit deeply captivates him. His accidental journey through time occurs when rescuing Celebi from a Pokémon poacher in the forest, transporting both to Ash’s timeline. In this future, Sam encounters Ash Ketchum and swiftly befriends him. Alongside Ash’s companions Brock and Misty, they shield Celebi from the pursuing poacher. Throughout their shared ordeal, Sam sketches Ash’s Pikachu sleeping beside Celebi in his notebook. He witnesses Ash’s courage and compassion firsthand during threats to Celebi, including its apparent death and subsequent revival by other Celebi. Sam returns to his original time by the film’s end, retaining the sketchbook. As Professor Oak in adulthood, he preserves this notebook in his closet, its drawings serving as proof of his encounter with Ash and Celebi. Oak recognizes Ash during their Pallet Town meetings but conceals their past connection and his identity as Sam. Consequently, Ash remains oblivious to their history, while Oak possesses foreknowledge of Ash’s future partnership with Pikachu and initial traveling companions. Sam’s childhood personality showcases curiosity and artistic skill through detailed Pokémon sketches. He displays bravery during the Celebi crisis. His choice to withhold the time-travel secret adds complexity to his mentorship of Ash in their present-day interactions.