Pokémon the Series: Sun & Moon Episode 125: A Timeless Encounter!
Episode 125 of 146 of Pokémon the Series: Sun & Moon, aired June 9, 2019, 25 minutes. Available with English subtitles and dub where released.
Episode summary
While Ash and his Pokémon train for the upcoming Alola Pokémon League, they accidentally startle a nearby Celebi. The Mythical Pokémon flees back in time—and brings Ash and Torracat with it! Unaware that he’s in the past, Ash meets a young boy who, unbeknownst to him, is actually a younger Professor Kukui. The boy wants to learn about Pokémon moves, and Ash and Torracat demonstrate some of their skills, even receiving a Firium Z from a Totem Trevenant. But the fun suddenly ends when Celebi transports our hero back to the present day. Ash wonders where the boy went, but he’s also happy to see all his Pokémon again!