In the Johto region, Kris the female protagonist from Pokémon Crystal started out on her adventure with her Chikorita. Her goal is to become the champion of the Johto League and seek out many Pokémon on the way.
One day, Kris is walking down Route 30 exiting from Cherrygrove City. She is close to Violet City to get her very first gym badge. However, her adventure came to a stop as her tummy started to growl a bit.
"Oh dear," Kris said after listening to the sounds of her stomach. "Seems like I put something in my stomach soon. There should be a berry bush nearby."
Instead of focusing on the adventure for the time being, she needed to find a berry bush to gather a couple of berries. She eventually found one of the berry bushes much to her relief after searching for a little bit.
"These berries look very delectable," Kris smiled as she plucked out a few from the maturing berry bush. "Berries, berries, berries, got to eat 'em all," she sang playfully.
Now that Kris is packed with the berries she harvested from the bush, she took one out and held in her hand as she examined it closely.
"I wonder what would happen if I eat this berry thingy?" she said. "Probably nothing--just a regular ol' berry."
Kris took a bite on the berry and gave it a taste test. The berry tasted like blueberries much to her delight and ate it until it was gone.
"That berry tasted pretty good," Kris smiled and patted her tummy. "Now I can continue on this journey and--"
Her speech was cut off as the effects of the berry she just ate kicked in. The first thing she noticed is her skin tone changing from pale to a darker bluish color. She then became blue all around her body and then began to swell up bigger.
"Eep! I'm turning into a blueberry!" cried Kris in astonishment. "How is this happening?!"
Kris continued to swell up slowly but surely rounding out into a spherical shape. As she grew larger and rounder into a giant blueberry, her hands and her feet were absorbed deep into her growing body. Her breasts also increased in size becoming no bigger than gigantic yoga balls. Additionally, her cheeks also became puffy and round like she swallowed a Qwilfish. By the time she stopped growing any bigger, she measured up into a 7 feet blueberry in diameter.
"Too bad I can't move in this shape," Kris said with a frown on her face. "But it's not so bad being a blueberry," she said changing her face to a happy smile and flapped her hands joyfully.
At first Kris felt uncomfortable about growing into a blueberry but in the end, it wasn't so bad after coming around and finding the fun of being a cute and a happy blueberry trainer she is.