Ash:
Different lessons for the new trainer will require Ash to rotate reserves in and out, so old favorites like Charizard, Lucario, etc. will reappear throughout but, like Nemona in game, he decides to start with a team to be on level with his mentee. His main arc is 'Starfall Street' from the games. While filling a Nemona-esque role as the new trainer's mentor, Ash is recruited by the mysterious Cassiopeia to bring down Team Star. At some point, Ash and Iono take care of challenging crybaby Toxels who evolve into Toxtricities. Befriends Miriadon while New Trainer befriends Kiraidon. Since Ash doesn't attend school technically, he will not be required to wear a uniform.
New Trainer:
New Trainer is hot-blooded, headstrong and a student at Naranja Academy. An orphan boy raised in the wilderness whose companion Pokemon is a Quaxly. He was taken in by Clavell, who has a soft spot for him. Because he is messy and wears his uniform wildly, he is often mistaken for a member of Team Star. His storyline is focused on the 'Victory Road' storyline from the games, taking on the Gym Challenge and being mentored by Ash. When Capsakid evolves into Scovillain, it has a 'disobedient' arc with one of the heads not wanting to listen, triggering Scovillain's ability, Moody. Befriends Kiraidon while Ash befriends Miriadon. Constantly argues and disagrees with Iono, their relationship reaches a head when he challenges her last in his Gym Challenge and they admit their mutual respect for each other.
Iono:
Iono is a streamer/influencer and also a student at the Uva Academy who happens to be a super-fan of Ash's, having watched his matches in the Alola League and the World Coronation Series. She catches an Electric Tera-Type Sprigatito. Her storyline focuses on 'Path of Legends' from the games, which she initially wants to take on for streaming views. She can come across as self-centered and eccentric, but throughout the series, her layers are peeled back and she's revealed to be caring. Iono steps back into her Gym Leader duty to face New Trainer when he reaches her town, choosing to face her as the last Gym Leader in his challenge. At some point, Ash and Iono take care of challenging crybaby Toxels who evolve into Toxtricities. She calms and befriends Iron Treads enough in her final 'Path of Legends' encounter, that it asks to join her team. While in school, Iono wears a Uva uniform but while traveling, she is in her usual attire.