Upon arrival, Ash and Chloe will arrive in Paldea, and Goh has gone a long way in his goal of catching many Pokemon.
Chloe starts school after transferring from Kanto and Ash decides to help her teach her all about Pokemon.
In Cabo Poco they are to meet Nemona, the regional champion of Paldea, who is to show them the way to school.
On the way, they encounter two legendary pokemons - Koraidon and Miraidon.
Both Pokemon form a small interaction with Ash and Nemona - they are interested in them.
Somewhere both pokemons disappeared, but the three of them were delighted to meet unknown species of pokemon, on the way there is another obstacle - Arven, he is looking for some pokemon, but he quickly gave up and also joins them.
Before entering the school, everyone encounters another obstacle again - some hooligans from Team Star are disturbing Penny, they intend to help her.
At school, they finally meet the most important person - Principal Clavell. Ash, delighted with the school, decides to join as well, and coincidentally finds himself in a class with new characters who have recently met. Finishing their performances with their new classmates and teachers, only Ash and Chloe have to go to the principal's office again - as it turns out, choosing a new starter from the region of Paldea. Ash and Chloe have a partner yes, but the principal insisted on choosing them due to the need to study at school.
Ash chooses a Fuecoco and Chloe getting a Sprigatito, they find them cute and love them.
While learning, all students will not only have to sit in the classroom and learn only by staring at the teacher and the blackboard, they will also have to learn on the premises, outside the school. As usual, it should be similar in the Sun & Moon series. Mela, one of Team Star's bosses, arrives at the school looking for Ash to avenge her teammates - the other bosses watch her fight as well, and she ends up being quickly defeated. They quickly moved away after losing the fight. Penny watched this and was going to thank Ash for his help and offered to help him defeat all the Team Star bosses, but the conversation was interrupted by Geeta, the second regional champion, leaving Ash completely shocked and confused as to why this region had two champions. Geeta, accompanied by the Gym Leader Iono, offered him a challenge to the Elite Four, knowing that he was too strong - after all, they are well informed that he is a recent World Champion. Iono came just to get Ash's photo and autograph, and to pet his Pikachu. Ash runs away from her with a barrage of questions trying to stream it.
Nemona came to the scene Iono made, surprised by Geeta's coming to school. The two champions invite Chloe to take part in the Gym Leader Challenge - they also inform her that Ash has been doing the same in other regions for a long time. Ash chose a much bigger goal - to defeat the Elite Four, Geeta and Nemona and Chloe chose to defeat the Gym Leaders along with Nemona - Ash was completely confused as to why she wanted to do this - she claims to want to make Chloe an equal rival. Eventually, it was decided that Ash would train Chloe to fight Pokemon, and Penny, dissatisfied with their choice, gave up and decided to help them based on learning from the computer, using her own skills.
Arven - last of all, has been eavesdropping on everything and is suddenly interested in joining the crew to travel around the region on holidays or after school. Nemona also joins these companions, it suits her better to travel with friends than alone.
Chloe - beginning trainer who is starting to learn about Pokemon battles.
Ash - Chloe's mentor, he teaches her everything he can, although sometimes he is not good at teaching, he is helped by Nemona.
Nemona - Ash and Chloe's new rival. Ash's rival therefore the two train hard together for their final battle after the Elite Four challenge. Unlike Ash, she gives Chloe a head start knowing she is still a novice Trainer.
Penny - a quiet and calm person, although she often uses the computer to answer questions from her friends. She knows too much about Pokemon.
Arven - A supportive companion who cooks food for everyone traveling together. Such a new Brock, but without infatuation with women. He still cares for his sick Mabostiff.
I won't go into too much detail too much as it will walk through the entire region of Paldea. However, I am highlighting only a few:
1. Together, the traveling companions will fight against all Team Star, who Penny eventually reveals her secret that she founded the team.
2. They all fight one Pokémon Titan at a time - to their surprise, Koraidon and Miraidon sometimes come to help them.
3. Chloe defeats the Gym Leaders one by one starting with Katy and ending with Grusha. She participates in the Pokemon League, which will lose in the 1/8 round, against Nemona. Nemona officially becomes the champion of the Pokemon League.
4. Ash defeats all E4 plus two champions with only his new team.
5. All five of them save the region of Paldea in Area Zero, Ash and Nemona defeat two AI professors and save Legendary Pokemon that will later officially join their team.
Full team of companions at final stage:
Ash: Pikachu, Armarouge, Koraidon, Kilowattrell, Greavard, Flutter Mane.
Traded away Skeleridge for Greavard with Arven.
Chloe: Eevee, Meowscarada, Clodsire, Oinkologne, Maushold, Fidough
Nemona: for Ash - Pawmot, Ceruledge, Miraidon, Flamigo, Lycanroc, Iron Valiant.
Just catch attention that she have a very opposite of Ash's whole team.
for Chloe - Quaxuawell, Pawmot, Grafaiai, Tauros, Brambleghast, Scovillain
Arven: Mabostiff, Skeleridge, Torkoal, Klawf.
Traded away Greavard for Skeleridge with Ash.
Penny: Umbreon, Espeon, Sylveon.