Delia Ketchum joins Ash and Professor Oak on their flight to the Unova region in the introductory episodes of *Pokémon: Black and White*. During the journey, Team Rocket's attempt to capture Pikachu coincides with a storm, causing Ash and Pikachu to become separated from Delia and Professor Oak. They reunite later near Nuvema Town, facilitated by Professor Juniper.

After confirming Ash is safe, Delia stays in Unova only briefly before returning to Pallet Town in Kanto, departing once Ash formally starts his Unova journey. She does not travel with him through the region.

Upon Ash's return to Pallet Town after concluding his Unova adventure, Delia welcomes him home. She observes the state of his backpack as proof of his efforts and sews new clothes in preparation for his next journey. When Ash announces his plan to travel to Kalos, Delia momentarily leaves the room, causing concern, but returns smiling to present the new clothes and wish him luck. At the airport later, she remarks that Ash's readiness for new adventures is typical behavior for someone his age.

Delia's established background remains consistent: she is Ash's mother, primarily managing the household in Pallet Town and caring for her Mr. Mime, known as Mimey, which assists with domestic chores. She maintains her characteristic supportive yet occasionally overinvolved parenting style, preparing Ash's travel gear and expressing pride in his endeavors. Her role in *Black and White* is confined to these introductory and concluding episodes, with no significant involvement in the main narrative of Ash's Unova journey.