Bonds of Mega Evolutions

What happened prior to this story.

I'll split the sections into series.

Ultra Sun and Ultra Moon:

Few days after Ash revisits Alola, he and his classmates are notified that new classmates have joined the School. The first one that is introduced was a girl Ash knew after their reunion in Kalos... It was Serena. The two instantly recognized each other, and Ash hugs Serena in front of everyone, much to their surprise.

Later, Ash and Serena runs into the other new classmates, Sun 'Ray', Moon, and Hau. Sun tells Ash if he remembers his Greninja, to which Ash says that he does. Sun then whistles towards the bushes, and out comes Ash's Greninja. Ash recatches his Greninja afterwards.

But soon Team Rocket appears and tries to kidnap Serena, but Ash decides to deal with the trio, and gets in sync with Greninja. But inadvertently gets in sync with Pikachu, Decidueye, Lycanroc, and Incineroar as well, transforming them into Ash-Pikachu, Ash-Decidueye, Ash-Lycanroc, and Ash-Incineroar respectively. Petrified, Team Rocket just looks at the Battle Bond quintet.

They release Serena, but were not spared from Ash's Pokemons. Ash-Pikachu released a Thunderbolt 10 times the strength of a Raichu's Thunderbolt, and Team Rocket is sent blasting off once more. Ash and his Pokemons then collapses out of exhaustion, much to Serena's worry.

After they wake up, Serena thanks Ash for saving her. She then reveals her feelings for him and says that she loves him. As she looks down, waiting for rejection, Ash smiles and pulls her in for a hug, revealing that he loves her too. Ash and Serena then kisses each other, as everyone looks at them.

Ash, Serena, and their Classmates then visits Kalos, to find not only Clemont and Bonnie, but also Misty, Brock, Gary, May, Max, Drew, Iris, Cilan, Dawn, Trevor, Shauna, and Tierno. Bonnie is happy that Ash and Serena are now Boyfriend and Girlfriend, then looks at Sun and Moon and asks Sun if Moon is his Girlfriend. Sun is shocked and responds with ''G-Girlfriend?! You've got the wrong idea!'', until Bonnie laughs and reveals that she was only kidding.

Ash and Serena then hears a voice through their heads, and they soon catch notice of a gold colored wind. The voice did not tell them its name, but told them that they should follow the gold wind.

Ash and Serena followed the wind to a city in the south in the Kalos region. The voice then guides them to a cave, and leaded them to a Chamber of Sleeping. The gold wind circles around two relics, as if telling Ash and Serena to place a hand on their respective relic, before going into the big stalagmite in the center of the chamber.

Ash and Serena placed their hands on their relic, and the big stalagmite opened up to reveal a 16 year old boy inside it. As he awoke, Ash pulled Serena close, unsure about what the boy might do. But the boy just approached them, before giving them the offer of goodwill: A Handshake. The boy smiles at them, and says ''My name is Lukas.''

Ash and Serena then exit the chamber and cave with Lukas. The three then jump up on Charizard's back, and fly back to their friends. When they arrive, their friends are happy to see them again, but is surprised to see Lukas the first time. After Lukas introduces himself to everyone, Ash asks him why he was trapped in the stalagmite, to which Lukas replies that he wasn't trapped in it, but had slept in it for centuries.

When Ash and his friends runs into Miette (again), the blue haired female takes Ash's hand and is about to say that she loves him. But Lukas attacks her, yelling that Ash and Serena are boyfriend and girlfriend. He then calls her a cockroach that no-one loves, this causes Miette to cry and yell at Lukas, calling his sword (The Tsunami Blade) an ''Rusty letter-opener'' before running away, much to his surprise.

Miette then encounters a guy named Calem, and to her surprise, he called her beautiful, a word no-one has ever called her before. Calem and Miette then search for Ash and his friends to try and befriend them.