In the anime, Ash was sent to Johto to deliver the GS Ball to Kurt for examination and discovered Azalea Town suffering from a drought. Ash accidentally stepped on the tail of a local Slowpoke and was chased by an angry mob, but Kurt disguised him and his friends in Slowpoke costumes, saving them. Kurt resided in Azalea Town, where Slowpokes were considered sacred due to their mythical ability to bring rain. Ash and his friends met Kurt while investigating Slowpoke Well after hearing strange noises coming from it. It turned out that Team Rocket was attempting to steal the Slowpokes. Ash helped recover the Slowpokes and defeated Team Rocket.
Later, Kurt received the GS Ball. Ash hoped Kurt would craft special Poké Balls for him. As gratitude for their help, Kurt gave Ash, Brock, and Misty each a Fast Ball. Ash and his friends gathered Apricorns, and Kurt crafted Lure Balls for Ash and Misty, and a Heavy Ball for Brock. In the latest episode, Kurt is still studying the GS Ball.
In the manga, Silver obtained a Heavy Ball from Kurt to catch an Ursaring. Kurt warned Silver that only experienced trainers could effectively use his special Poké Balls. Later, Gold encountered Maisy and Kurt. Kurt explained that his ancestors were once the sole creators of Poké Balls until companies began mass-producing them. Kurt held a slight grudge against Gold for mocking his Apricorn Balls, stating Gold wasn't experienced enough to use his special Balls, which annoyed Gold. He then challenged Gold to catch a Pokémon using one of his balls, and if he couldn't by dusk, he would have to become Kurt's apprentice, which Gold accepted.
Kurt crafted a Friend Ball for Gold, and later, Gold and Silver used their custom Poké Balls to capture a Teddiursa and Ursaring. Silver kept Ursaring for himself while Gold gave Teddiursa to Maisy. Kurt then appeared at Slowpoke Well, finding a mass of Team Rocket Grunts tied up and defeated, with everyone wondering who did it. Later, the Masked Man forced Kurt to hand over his plans for the GS Ball.
In their youth, Professor Oak, Agatha, Kurt, Pryce, and the old couple running the Goldenrod City Pokémon Daycare were close friends. To cheer Pryce up, Kurt helped write the lyrics for "Riding On The Stars," which DJ Mary later sang.
