Ash Ketchum became the first Pokémon League Champion of Alola.
Ash wins the inaugural Alola League in Pokémon the Series: Sun & Moon—Ultra Legends. Because the Alola League was newly established, its winner became the region’s first official League Champion.
The victory was significant because Ash had competed in Pokémon League tournaments across several regions without winning the main regional title. Earlier accomplishments included reaching finals or other high placements, but Alola was his first regional League championship.
The Alola storyline differs from the traditional gym-based structure used in several earlier regions. Ash attends Pokémon School, completes island challenges, and competes in the new League after it is established.
Ash later achieved another major milestone by defeating Leon in the World Coronation Series, becoming the world champion of the anime’s competitive circuit. That later title is distinct from his first regional League championship, which occurred in Alola.