After dreaming that he made a promise to the Legendary Pokémon Solgaleo and Lunala, Ash has a hard time waking up. On his way to school, he’s sidetracked by Tapu Koko, who guides him to a strange little Pokémon that looks like a cloud of stars. Lillie nicknames it Nebby, and Ash remembers his dream: he promised to take care of it! This attracts the attention of Lillie’s mother, Lusamine, the head of the Aether Foundation. She and her colleagues come to meet Nebby and offer to take care of (and research) this unknown Pokémon. But Ash is resolute in his promise, so Nebby’s identity is a mystery for now!

The Pokémon School class is sculpting with clay today! But while our heroes muse about various Pokémon and places, they disappear one by one—first appearing at the scenes of their musings, then reappearing back at school! They soon realize Nebby had used Teleport to take them to the places and Pokémon they were thinking about. Meanwhile, Team Rocket is determined to catch Nebby. They succeed, but thanks to Teleport, Bewear carries the trio off...and Nebby makes its way back to Ash—all by itself! After Ash and Pikachu visit the places the rest of the class saw earlier, one thing becomes obvious: Nebby is growing up!

Our heroes visit Aether Paradise, part of the Aether Foundation run by Lillie’s mother, Lusamine. An impressive variety of Pokémon live in the conservation area, including a group of Ditto who need their shots! Professor Burnet recruits Ash and friends to help with the vaccinations while Lusamine is busy on the phone, but one of the Ditto escapes and leads our heroes on a merry chase as it keeps transforming. They eventually catch it when it disguises itself as Snowy—and Lillie realizes she can’t touch it! Meanwhile, the Team Rocket trio has scored jobs at Aether Paradise, and they’re hot on Nebby’s trail when they stumble into Faba’s mysterious laboratory…

When Ash gives Lycanroc a bath, an accidental splash of dirty water unleashes Lycanroc’s surprisingly red-hot temper! Then, when our hero wonders aloud what Gladion is up to, Nebby teleports Ash and Pikachu to him. They meet Silvally, a Pokémon created to defeat Ultra Beasts—and Gladion is convinced that Nebby is one! Suspicious, Gladion wants to know what Ash is up to, and our hero suggests a battle so he can find out! Ash’s Dusk Form Lycanroc faces off against Gladion’s Silvally. Lycanroc battles magnificently, but another temper tantrum betrays its inexperience, and Silvally wins. But Gladion decides Ash is trustworthy, and their friendship starts to grow…

Our heroes are having a sleepover at Professor Kukui’s house, and Professor Burnet agrees to join them! Everyone has a good time, but there are a couple of hiccups: during a game of Z-Move poses, Kiawe accidentally unleashes Turtonator’s Inferno Overdrive in the living room, and then Professor Burnet’s Munchlax eats everything she cooked for dinner! That night, when Lillie has trouble sleeping, she talks with Professor Burnet, who offers some advice about her family. The next day, Nebby unexpectedly whisks her away to visit her brother—and his partner, the mysterious Silvally, who leaves her terrified and apparently unable to touch Pokémon again!

After accidentally seeing Gladion and coming face-to-face with Silvally, Lillie is once again unable to touch Pokémon—but she’s determined to change that! With Nebby’s help, she embarks on a journey to recall the memories behind her fear. But Faba wants none of it, having been responsible for Silvally’s creation in the first place. Vowing to make sure Lillie never remembers her past, Faba captures her, and she’s again filled with fear. But Silvally rescues Lillie, and when she remembers that it was the one who saved her in the past, her fear of touching Pokémon finally vanishes!

Lillie can touch Pokémon again! While our heroes celebrate, a disgraced Faba is determined to prove himself to Lusamine by summoning an Ultra Beast—the same one that threatened Lillie years before. He kidnaps Nebby and convinces it to teleport him into his research lab at Aether Paradise. Ash, Gladion, Lillie, and Lusamine go after Faba, arriving just as a panicked Nebby transforms into a chrysalis and the Ultra Wormhole begins to open! The Ultra Beast known as UB-01 Symbiont emerges and attacks Lillie—but Lusamine throws herself in front of her daughter, and the Ultra Beast engulfs her instead and takes her back through the wormhole!

Our heroes are in shock after Lusamine’s disappearance through an Ultra Wormhole, and they want to help get her back. But Gladion insists it’s a family matter, and he and Lillie set out on their own rescue mission. The Pokémon School class still wants to help, though, so Kahuna Hala directs them to the Altar of the Sunne on Poni Island. Meanwhile, nearing the altar, Gladion and Lillie encounter a Totem Kommo-o! With Snowy and Silvally, they defeat the Dragon-type Pokémon. Then, when the siblings rejoin the rest of our heroes, Ash again tries to convince Gladion to let everyone help. And when Lillie agrees, Gladion finally understands…

Our heroes are all gathered at the Altar of the Sunne, along with all four of Alola’s Island Guardians. Lillie and Gladion ask the Island Guardians for help to rescue their mother, Lusamine, who has been taken through an Ultra Wormhole by a mysterious Ultra Beast. After Tapu Koko and the others perform a ritual, little Nebby evolves into the mighty Solgaleo—one of the Legendary Pokémon of Alola! At Solgaleo’s invitation, the Pokémon School students climb onto its back. With the help of a new Z-Move, Solgaleo opens an Ultra Wormhole and carries them through, off to rescue Lusamine from the Ultra Beast!

Our heroes have made it through the Ultra Wormhole, but when they find the captured Lusamine, they’re shocked to find she wants nothing to do with them! With an Ultra Beast controlling her mind, it’s up to Lillie, Ash, and friends to rescue her. Their Pokémon spring into action—but so do Lusamine’s Pokémon, who are also under the Ultra Beast’s control. Lillie gathers her courage and reaches out to Clefable, recounting the fun they had together in years past. Her reassuring persistence pays off, and Clefable breaks free of the Ultra Beast’s control. Meanwhile, riding on Solgaleo’s back, Ash presses on to find Lusamine—and the Ultra Beast.

Our heroes are battling hard against a group of mind-controlled Pokémon, and Lusamine is still resisting rescue. When Gladion realizes their attacks won’t stop until the Ultra Beast is defeated, Ash suggests the two of them use Z-Moves. Instead, Gladion and his Pokémon provide a distraction while Ash and Pikachu use a powerful new Z-Move: 10,000,000 Volt Thunderbolt! This finally defeats the Ultra Beast, and after Lillie pleads with her mother to wake up, Lusamine is finally herself again. Returning through the Ultra Wormhole, our heroes and Lusamine are reunited with Professor Kukui and Professor Burnet, and Lusamine gratefully gives credit to our heroes for saving her.

Following their journey through the Ultra Wormhole, our heroes return to the Pokémon School, where Lillie thanks everyone for their help saving her mother. Later, during a walk on the beach, Professor Kukui asks Professor Burnet to marry him! They aren’t planning a wedding ceremony, but our heroes have other ideas...a surprise ceremony awaits! Then, Lusamine asks the Pokémon School class to join the Ultra Guardians—a group that protects Alola from Ultra Beasts. And just after the bouquet toss, Solgaleo appears! Ash gets his wish and thanks the Legendary Pokémon for all its help, and he looks forward to seeing it again someday.

Our heroes are curious about the origins (and sleep habits) of Principal Samson Oak’s partner Komala. After telling the students how they met, Samson shows off Komala’s impressive skill at battling in its sleep! They get another lesson in sleep when Jigglypuff shows up at the Pokémon School! As always, its song makes everyone sleep, and they wake with angry scribbles on their faces…everyone except Komala. That gives Samson an idea… When Jigglypuff returns, Komala joins it in song. This makes Jigglypuff fall asleep, and Komala doodles on its face! Rather than being grumpy when it wakes up, Jigglypuff seems to think this is hilarious. Komala has a new friend!

Rotom Dex is excited to house-sit while Ash and the professors go shopping. But chaos ensues when a washing machine is mistakenly delivered—and there’s a Wash Rotom inside! Somehow, the Wash Rotom ends up inside Ash’s Pokédex, and Rotom Dex takes its place in the washing machine. After a series of accidental form changes, and even some time spent inside a TV, Rotom Dex yearns to be back inside the comfort of the Pokédex. It finally succeeds, but not for long—after a big shock from Pikachu, Rotom Dex accidentally inhabits the entire Pokémon Center!

After a day of shopping, Team Rocket encounters Mareanie’s first love and mentor, a Mareanie that still has feelings for its former protégé. Filled with jealousy, it evolves into a Toxapex and poisons James! In his poisoned stupor, James decides Mareanie should be with Toxapex instead of with him. When Mareanie overhears this, its sadness causes it to run away. But Toxapex can’t bear to see Mareanie cry, and it challenges James to a duel to win Mareanie back. After what turns out to be an underwhelming battle, James is victorious, and Mareanie joyously reunites with him and the rest of Team Rocket!

When Harper and Sarah tell Lana that a Pokémon saved them after they got lost in the woods, Mallow remembers the same thing happened to her and Lana when they were younger! The two friends decide it’s time to find this Pokémon, nicknamed Grandpa Forest, and offer it their thanks. Always up for an adventure, Ash and Pikachu tag along, too! Our heroes soon learn that Grandpa Forest must be a Drampa, and when they find its favorite bittersweet Haban Berry trees, they realize they’re on the right track. Then, after a brief scuffle with Team Rocket, Lana and Mallow joyfully reunite with their old friend!

The Pokémon School students, Professor Kukui, and Kahuna Hala are visiting Mount Lanakila on Ula’ula Island, where they meet Cerah, a star of the Pokémon Sled Jump event. With the help of her Alolan Ninetales, Cerah introduces our heroes to the sport, and Lillie and Snowy are excited to try it together—even regaining their confidence after crashing during a practice run. The two of them fly high in the competition, and Snowy shows off a new move: Aurora Veil! Although Kahuna Hala and his newly evolved Crabominable are the winners, everyone agrees that Lillie’s jump was excellent, and she’s excited to keep working with Snowy as a team!

Lusamine gives our heroes their first assignment as members of the Ultra Guardians: catch an Ultra Beast named Buzzwole, who emerged from an Ultra Wormhole on Melemele Island. Equipped with the latest technology, the Ultra Guardians locate the Pokémon, whose aggressive behavior seems to reflect its anxiety about being in a strange world. Ash and Kiawe notice Buzzwole has a habit of striking heroic poses—so they join right in! With Buzzwole’s guard down, Ash catches it in a Beast Ball, and it’s soon returned to its own world through the reopened Ultra Wormhole. Though our heroes will miss Buzzwole, their first mission as Ultra Guardians is a rousing success!

When Team Rocket encounters an Alolan Meowth, Jessie and James admire its clever demeanor—but our Meowth knows from experience that this lookalike is only looking out for number one! To Meowth’s chagrin, Jessie and James want Alolan Meowth to join Team Rocket, and it even comes up with a plan to catch Pikachu once and for all. But when the plan’s set into motion, Alolan Meowth is nowhere to be found! When it reappears at Team Rocket Headquarters with the Boss, Jessie and James realize they’ve been had. Meowth is filled with jealousy, but he can also breathe a sigh of relief, as things are back to normal again!

The mysterious Masked Royal and his partner Incineroar star in the Battle Royal, an Alolan tradition in which four Pokémon battle until the last one standing is the winner. Ash, watching on TV, can’t wait to get in on the action—and the next day, he gets his chance! At the Battle Royal Dome, Ash’s Litten charges right into the ring, determined to take on the impressive Incineroar. The Masked Royal accepts Litten’s challenge and invites Sophocles and Kiawe to round out the four. He defeats them all, but Litten is fired up—and during an unexpected rematch the next day, it evolves into Torracat!

Ash takes a trip to the marketplace and meets the local group of Passimians, who have a rivalry with the Akala Island Passimians. (exists only in Japanese) Original title: Satoshi and Nagetukesaru! Touchdown of Friendship!!

There’s plenty of excitement at the Pokémon School when Ilima, one of its most skilled graduates, returns for a visit. The students have heard plenty of stories of Ilima’s adventures with Eevee, and after sharing those stories with Ash and Lillie, they want to learn if the legends are true. Despite that popularity, though, Ilima’s reappearance has attracted the unwanted attention of Team Skull’s Tupp and his crew of Grunts.

Our heroes are learning all about Pokémon Ping-Pong, with Pokémon School graduate Ilima showing them the ins and outs of the game! Ilima plans to compete in an upcoming Pokémon Ping-Pong tournament, where he hopes to settle an old score and defeat Ikari, the winner in previous years. But while Ilima believes that consideration for his Pokémon partner is key to success, Ikari takes a more aggressive strategy. After Ikari berates his partner Mienshao during the heat of the tournament’s final game, the two lose coordination, and Ilima and his partner Smeargle emerge victorious!

One day during class at the school, an unrecognizable creature comes to Ash and the others. When they notice it, the creature disappears, but for some reason they can no longer see Pikachu around either. It appears Pikachu was taken away by the earlier creature. An agitated Ash starts searching for Pikachu, but suddenly runs into Team Rocket.

Ash is on his way to the Pokémon Center with Pikachu, Rotom and Poipole for the school's work experience program when he is stopped by the Team Skull grunts, who challenge him to a battle. The 3-on-1 battle backfires when something goes wrong with Zipp's Garbodor's Venom Shock and Team Skull is forced to retreat. At the Center, the Nurse Joy that works there has a bad cold, so Ash and the others decide to do her duties for her. With some minor hiccups (such as a mix-up about Pokémon Center uniforms and an unexpected delivery to Team Rocket's food truck), things go well, but Zipp keeps showing up, apparently seeking treatment for his Garbodor, who is suffering from Poison Clog. The gang aren't sure how to help Garbodor, but Nurse Joy appears and takes change of treating Garbodor with their help. By evening, Garbodor has been cured, but the Nurse Joy who treated Garbodor turns out to be a sister of the now-recovered Nurse Joy.