In the Kalos region, a boy named Ash Ketchum from Pallet Town in Kanto is traveling with his 3 friends. His childhood friend Serena, a gym leader Clemont and his little sister, Bonnie. As our heroes take a break from traveling while Clemont was preparing food, the two childhood friends  found something glowing in the distance. 

Serena: Hey Ash what is that?

Ash: I don't know but we should check it out.

And so Ash and Serena walked towards the glow and they see a crystal.

Serena: What kinda of stone is this?

Ash: I don't know Serena but it looks like an Eevee crystal.

As Ash was examining it, the crystal glowed very brightly forcing our heroes to cover their eyes as the two trainers also fell backwards and the glow stopped as the crystal disappeared.

Ash: *Rubbing his head while getting back up* What was that about?

As he continued to rub his head from his fall, Ash felt something growing from Paul's back. It was a small, fluffy tail. It grew a little bigger and was moving on its own. Being covered in soft brown fur with a light cream tip, the tail looked suspiciously like an Eevee tail.

Serena: *Shocked* Ash! You have a tail!

Ash: I have a what?!

Ash turned around and grabbed his new tail as his ears quickly changed into long, pointy Eevee ears that perched on his head, covered in brown fur. He lets go of his tail and felt his new long pointy ears.

Ash: My ears!

Serena also felt the same changes as Ash. She also grew an Eevee tail with a heart shaped cream fluff on it and her ears also became pointy.

Serena: *In fear* What's going on?!

Ash: The crystal is changing on bodies!

Just then the two were shrinking too. A mane of creamy fur was sprouting out of their necks. Their teeth turned into small fangs and their noses because small and black. Brown fur was spreading on them as they were getting smaller. Their clothes were getting baggy and their hands and feet got covered in fur and became paws as they fell off of Ash's large gloves and their large shoes. 

Ash: *Gasps* We're shrinking! And our clothing is getting bigger on us!

Their hairs also became brown but their styles remain the same along with their eyes, voices, hats and Ash's Z marks. They then shrank all the way down to Eevee size as their now loose clothing swallowed them and they passed out.

After the transformation was done, The two blonde hair siblings and the pokemon went out to look for Ash and Serena, eventually they found their clothes.

Pikachu (Worried): Pika Pi?!

Bonnie: Big brother, where are Ash and Serena? Last time they were standing right here looking at that crystal which is now gone.

Clemont: I don't know where they are now Bonnie.

Soon, they noticed the little bulge moving in Ash's large clothes that blanketed it until it reached the head of the jacket. A paw came out of the jacket followed by the second one and an Eevee wearing Ash's hat came out of the jacket. The Eevee opened its eyes revealing familiar light brown eyes. 

Eevee: *groans* What happened?

The siblings and Pikachu knew the voice. It was their friend from Kanto.

Clemont and Bonnie: *Shocked* Ash?! Is that you?!

Pikachu: Pika Pi?

The Eevee now knows as Ash looked up to them.

Ash: Yes it's me you guys.

Bonnie: What happened to you and Serena?

Ash: The crystal! It did this to us!

Ash then ran up to Serena's pile of clothing since he now can run and walk on four legs and tried to wake her up but she was still unconscious and underneath her clothes. Bonnie then grabbed Serena who also became an Eevee out of her large dress and handed her to Clemont as they headed back to where they were taking their break.

To Be Continued...