Ash Ketchum/Sun & Moon

Ash Ketchum is the main protagonist of the Pokémon Anime and a trainer from Pallet Town, aspiring to become a Pokémon Master.

Appearance
Ash wears a new outfit which is different than his previous outfits. He wears a white and blue striped short sleeved loose collared shirt, brown capris with red outlines with baggy pockets and red folded sleeves at the edge of his capris and shades of blue sneakers. His hat is red and black and the Poké Ball design is white. Ash wears a silver Z-Ring on his left wrist which was later changed into a Z-Power Ring.

As the member of Ultra Guardians, Ash wears an indigo and white Ultra Guardian uniform with light periwinkle accents as the edge of the short sleeves, collar and inlines of his uniform are black and wears a matching indigo gloves.

Personality
Since entering the Alola region, Ash is shown to be far more enthusiastic than he did in the Kalos region while at the same time kept his determination and his love for Pokémon. While Ash does retain his competence and experience, not getting upset over losing the Trial Challenges and defeating multiple Pokémon at the same time, he displays a considerably more childish and hyperactive demeanor.

Sun & Moon
Ash arrives in the Alola region on a vacation with his Mom, which Mimey won for them. After a nice Sharpedo ride, a run-in with a Bruxish that Lana caught on her line, a race with Grubbin then having some bad luck with a Bewear and some racing Tauros, Ash finds the Pokémon School where he meets Lillie, Mallow and Sophocles. Mallow mistakes Ash for a student and takes him to see Samson Oak, which conviently leads him to Delia and Mimey. Delia gives the Kantonian Vulpix Egg to Samson and Mallow shows Ash the rest of the school, including the classroom, where they meet Professor Kukui. After the meeting, Kiawe is confronted by Team Skull, who challenge him to a three on one battle, with the prize being his Charizard. Ash jumps in to help, defeating the Salandit and leaving the Zubat and Yungoos to be finished off by Kiawe and Turtonator's Z-Move, Inferno Overdrive. After seeing all of this, and receiving a Z-Ring from none other than Tapu Koko itself, he decides to stay with Professor Kukui and Rockruff while attending the Pokémon School. On Ash’s first day at school his new classmates give him some challenges before Tapu Koko showed itself which it takes Ash's hat before realizing it wanted to battle him and Pikachu. During the battle Tapu Koko helped Ash use the Z-Move Gigavolt Havoc with Pikachu but it shatter due to not doing the island trial which Tapu Koko left. When Ash's classmates explain the island trail Ash decided to do it to get another Z-Crystal with his classmate giving their full support for him. The next day, Professor Kukui gave him the Rotom Pokédex to get info on the Pokémon in the Alola region. When he tried to catch his first Alola region Pokémon, he gets a surprise attack by Team Rocket who tried to take Pikachu again but failed when the Bewear Ash saw when he was exploring on his first day at the region takes them away. Ash was able to catch his first Alola Pokémon, a Rowlet after befriending it when it got hungry and Rowlet wanting to be with him as well. Ash met Hala the Island Kakuna of Melemele island then he was there when he went to take the Island Trail and won when the Totem Pokémon Gumshoos gave him a Normalium Z-Crystal. Next came Ash's Grand Trial against Kahuna Hala through the hardwork of Rowlet and Pikachu, Ash won his Grand Trial. But as soon as he was going to take the Fightingium Z-Crystal as his reward Tapu Koko swapped it for the Electrium Z.

Ash catches Rockruff, the Pokémon Professor Kukui was taking care of, after helping it win a battle. Some time later Ash and Pikachu got challenged to another battle by Tapu Koko but the force of the battle caused Pikachu to fall off a cliff with Ash trying to save him but Tapu Koko saved them both with no winner. But declared that they would get stronger and win the next time they battle. Ash and Pikachu went to an island to spend time thogther during which they got to see Tapu Lele, the island guardian of Akala island. Then, Ash and his Pokémon come across Litten again this time find it with Stoutland in its new home to discover Stoutland is trying to teach it Fire Fang but with no success. Some time later, Litten finds Ash hoping he could help his ailing mentor, they make it to the Pokémon Center but only to find out Stoutland is nearing the end of its life and wonder if Litten knows. So Ash decides to keep them company to find out the pair is gone back to their home, then Litten discovers that Stoutland is gone and when Litten couldn't find his mentor anywhere he finally accepted Stoutland's passing. He finally agreed to his mentor's last wish and joined Ash's team making Litten his third Pokémon he caught in Alola region.

Ash came across Gladion, Lillie's brother, thus becoming rivals and good friends also through Gladion Ash learned along with deciding that he would take on Akala island Grand Trial to get Rockium Z so he can use Rock-type Z-Moves. Lucky for Ash, he was going on a field trip to Akala island with his classmates but before they did they meet Olivia, who's the island Kahuna for Akala island.

Ash then went with Mallow to collect cooking herbs when Totem Lurantis challenged him. Ash won and defeated Lurantis and received the Grassium Z and then ate dinner with his friends, Professor Kukui and Olivia.

After Ash got the Grassium Z, they challenged Kahuna Olivia with Rowlet and Rockruff while Olivia used Midday Lycanroc and Probopass. After defeating her, Ash received the Rockium Z so Rockruff could use Continental Crush.

At night, Rockruff ran off to train Ash found dust from Tapu Lele after Rockruff got away again then Ash and the co. went to find him with Professor Kukui and Olivia then Olivia and Gladion’s Lycanroc found it and dragged it to the Ruins of Life where Tapu Lele tried to heal but failed the first time. After Ash arrive along with his Pokémon, Professor Kukui and Olivia it used Drain Kissed on Ash and the 2 Lycanroc which helped heal Rockruff along with giving the energy back to them. Then Rockruff evolved into Dusk Lycanroc right before Ash and co. went back to Melemele Island with Professor Kukui.

Then the next day, Lycanroc and Ash were using the Rockium Z against Team Rocket, but when it failed to do so, Kiawe had to finish them off so then Ash and Lycanroc kept training. After Mimikyu's disguise broke and then Meowth and James found them again, they attacked back, but Ash tries the Rockium Z again and did it correctly.

Alola Island Challenges

 * Verdant Cavern Trial (Normalium Z)
 * Melemele Island Grand Trial (Electrium Z)
 * Brooklet Hill Trial (assisted Lana; did not receive Z-Crystal)
 * Lush Jungle Trial (Grassium Z)
 * Akala Island Grand Trial (Rockium Z)

Tournaments

 * Pokémon Pancake Race: Runner-up
 * Charjabug Race: Winner with Sophocles and Kiawe

Trivia

 * Unlike the previous anime series, Ash does not wear fingerless gloves with his outfit in Sun & Moon.
 * With the capture of Litten, this is the second time since the Sinnoh region that Ash catches two out of the three starter Pokémon.