K so basically it's set in Alola and Principal Oak, prior to Ash coming to Alola, asked if for a week they could borrow a trainer's Pokemon. Professor Oak asked Ash, as he had the most Pokemon. Ash agreed, but then ended up in Alola during this week. Also Serena and Gary are here because this was originally planned for a book I've since deleted. So like, they also haven't gone to Kanto.

Specific Pokemon-Trainer duos:

-Ash~Gible
-Kiawe~Charizard
-Lillie~Hawlucha
-Serena~Noivern
-Mallow~Bulbasaur
-Sophocles~Noctowl
-Lana~Corphish
-Gary~Gliscor

"Ash, a Pokemon School wants to know if they can borrow some Pokemon from my lab for a learning week. Since you have the most, it made sense to ask you. The School's principal is my cousin, so I know that they'll be in good hands. There's not enough students for every Pokemon to need to go, but quite a few of them will." Professor Oak said.

"Let me go ask them." Ash had replied.

After briefing with his Pokemon, Ash had returned inside, Pikachu still with him, with an exact list of all of the Pokemon's willingness to go. Pokemon such as Tododile and Muk were some of the most willing to go, whereas Pokemon such as Infernape and Scraggy were some of the least. Some outliers included Charizard, who probably just wanted to mess with some kid's grade to be completely honest, and Torterra, who didn't want to be lugged around a school.

He handed Oak the list, who nodded before speaking, "Alright, thank you."

~~~

"Alright class, today we are going outside to pick a pokeball from a box. Then, you will take care of the Pokemon for the week." Kukui said.

Ash and Pikachu were holding back laughter, which Gary caught on to and almost started laughing as well.

"A trainer who keeps their Pokemon at my cousin's lab allowed us to borrow some of their Pokemon and we couldn't make this possible without them allowing us to do so." Principal Oak spoke.

Serena turned to Ash, who she noticed was trying his hardest trying not to die of laughter and smiled, realizing why.

Kukui went on to explain how they would be graded on this.

"Ash, Gary, what's so funny?" Kukui asked after finishing, noticing the two trainers holding back laughter.

Knowing Ash would erupt with laughter if he spoke, Gary spoke instead, "N-Nothing!"

Kukui raised an eyebrow, but didn't push further, "Alright, let's go outside."

Samson Oak had left after saying his bit, assumingly to get the box of Pokeballs.

By the time they got outside, the boys' laugher had finally calmed. Pikachu, on the other hand, was still trying not to die of laughter. However, he had finally calmed down by the time Principal Oak got outside with the box of pokeballs.

Once Principal Oak sat the box down, the students were given a speech on how the Pokemon need to be treated with respect and stuff like that. Afterwards, the students were allowed to pick a pokeball.

Kiawe was the first to pick. After he grabbed the pokeball, he was immediately pestered by Ash, who happened to know that it was Charizard's pokeball.

"Are you sure you want that one?"

"Yes."

"Are you really really sure?"

"Ash, I'm sure."

"I don't think you should take that one."

"Well you saying you think I shouldn't take it makes me want to take it more."

"Fine. I wish you the best of luck with that one then."

At this point, everyone apart from Pikachu and Gary were confused. Serena was much less confused then her Alolan classmates, but still didn't know what Pokemon Ash was talking about.

"Why would I need luck?"

"After he evolved and before I spent an entire night thawing him out, he was an absolute brat. He probably won't listen to you, at least until you prove yourself, to be completely honest."

"Wait, these are your Pokemon?" Mallow asked.

"Yeah." Ash replied, "I can help you guys pick one that I think would work well with you."

"That'd be wonderful." Lillie spoke.

Ash turned to Principal Oak and Professor Kukui, "It's fine if I help match the others and just take whoever's left, right? And if we set a no releasing Pokemon form their Pokeballs until they're all handed out rule? Since they're all my Pokemon anyways and I wouldn't be able to help with my Pokemon greeting me..."

At the nod from both adults, Ash turned back towards Lillie, who was the closest to him and the box.

"Lillie, hm... Something tells me you and Hawlucha would be a good match." Ash spoke, handing Lillie the fighting type's pokeball.

"I think I see it too." Serena spoke up, "I feel like since I'm staying with Lillie you should give me Noivern since those two are extremely close."

"You read my mind, Sere." Ash replied, handing Serena the dragon type's pokeball, "Plus, you already have experience with him. You were there when he hatched, after all."

"Gary, how about Gliscor?" Ash spoke again, picking up the ground flying type's pokeball.

Gary nodded, understanding why Ash chose Gliscor for him.

"Me next!" Mallow exclaimed.

Ash picked up two pokeballs and looked at them both before holding them both out to Mallow, "Take your pick!"

Mallow ended up selecting the pokeball on the left and Ash sat the pokeball on the right back in the box. Ash then dug out another pokeball and handed it to Sophocles without giving it a second thought. He then dug out three more pokeballs, holding them all out in front of Lana.

"You want me to pick from these three, right?" Lana asked.

Ash nodded. She reached for the right one before maneuvering to the middle one.

Ash stared at Sophocles for a moment, "I don't own any electric types other than Pikachu, but I think I have an idea..."

He reached into the box and pulled out a Pokeball, handing it to Sophocles. Ash then continued to help the other classes as his classmates stood back, chatting amongst themselves.