Our heroes have finally arrived in Aspertia City, and on Professor Juniper’s advice, they want to visit the new Gym—which doubles as a schoolhouse where Trainers-to-be can learn all about Pokémon! They meet a young teacher named Cheren, who also happens to be the brand-new Gym Leader. Ash wastes no time in challenging Cheren to a battle, but it has to be an exhibition match because the battlefield isn’t finished yet.
They make plans to battle later that afternoon, and in the meantime, Cheren shows our heroes around the school. During the tour, Axew wanders off to explore on its own, and when Pikachu goes after it, they both get into some very noisy trouble—which is broadcast through the school’s speaker system. The sudden loud noise frightens the Pokémon living in the school’s Pokémon house, and they escape through an open door! Everyone splits up to look for them, and after a few complications, Ash rounds up some well-camouflaged Sunflora, Iris retrieves several mischievous Minccino from the school’s kitchen, and Cilan and Pansage manage to get a reluctant flock of Ducklett out of the pool.
Cheren takes a head count of the Pokémon as they are returned to the Pokémon house, and realizes there’s still one Shinx missing. Our heroes track it down, but the Shinx is frightened, and when two students corner it in an attempt to bring it back, it attacks them! Cheren dives in to protect them and calm the startled Shinx, and the two students tearfully confess that they were trying to catch it because they’re the ones who left the door to the Pokémon house open.
All’s well that ends well, and it’s time for Ash and Cheren’s battle! With the students cheering him on, Cheren demonstrates formidable skill with his Herdier, and though Ash and Oshawott get in some powerful attacks, the battle goes to the new Gym Leader. Cheren thanks Ash for helping him to bolster his confidence, and resolves to stop overthinking his many jobs as a Gym Leader, teacher, and role model for his students. And saying goodbye, our heroes are off once again to the White Ruins!