The breeze played through the grass and tickled the back of Fio’s neck, and the trainer smiled.

It was truly a lovely day in a deep, borderline uncharted part of the region. The young woman was clad in her usual traveling gear: black tights under an ochre skirt, a blue-and-white tee with the sleeves rolled up, with her voluminous white hair pulled behind her head with a large pink bow. A smaller ribbon of the same color and material was tied around her neck.

Stretching her arms out, Fio splayed herself in the soft grass. There was no one around for miles, and the day was so very lovely. She found herself in danger of dozing off…

Her eyelids brushed down, but then a sudden sound snapped them open. She rose to see a shape coming her way through the tall grass, a fan of off-white tails trailing behind it. Fio recognized it instantly: a Ninetales.

The fox pokemon emerged from the grass, his gaze fixed intently on her. He cocked his head as if studying her for a moment, and then fanned his tails out wider. The air shimmered like heat rising off asphalt as power crested off the pokemon.

Fio had no idea what the Fire-type’s intentions were, and apprehension had been threading through her. Once the power hit her, however, she blinked. She was feeling… different. All of her worries and her tension slowly drifted away, like dandelion seeds caught in the wind. She felt… nice. Tranquil. Relaxed.

The relaxed feeling continued even as the Ninetales’s power continued washing over her. Blinking at a new, somewhat scratchy sensation down at her arms, she glanced down to see that patches of yellow fur were growing in over her coffee-hued skin.

Normally, such a development would have startled, even frightened her—but with that tranquil feeling still washing over her, acceptance settled in soon enough. She found that she didn’t particularly mind.

The fur continued growing elsewhere on her body, spreading patchwork to Fio’s legs, her torso, even her neck and face. Grimacing at the way her new fur was rubbing against her clothes, the trainer began casting them off. Any worry that she was baring herself to the world—or that the Ninetales was still there, watching, tails fanned out—was quickly put down by the tranquility.

Even as she cast off her clothes, she was aware of other changes playing at her body. Her limbs were shortening, and a tugging sensation at her ears told her they were growing longer. Her hair was beginning to vanish, so she undid her hair ribbon. Then, almost mechanically, she reached to undo her neck bow as well.

“Wait.” The single word came from the Ninetales, who rose and trotted over to her. Even amidst her tranquil feeling and the crescendo of sensations her transformation was giving her, she found herself astonished. How could she understand him? Why?

“The ribbon… is cute on you,” the Ninetales said. His voice was low and honey-smooth, confident without being aggressive, and Fio found herself blushing at it. (Blushing? At a Ninetales? This was strange… but, as before, incredulity shifted to acceptance so, so easily.)

“You think so?” she asked, only barely cognizant that her own voice sounded different. She was now smaller than the Ninetales, and still shrinking by the moment. Her limbs were much shorter now, and golden fur was spread everywhere: her tummy, her back, even on…

Her pussy.

Fio blushed as she realized the Ninetales’s attentions were fixed on it. His head rose to fix his eyes on hers, and she found herself burning with unanticipated arousal. Whatever she was turning into, it liked the Ninetales’s attentions.

“May I?” he asked. Fio could only nod, breathless.

He settled down on his paws, leaned his muzzle into her slit, and began lapping.

Delight blossomed through her, and Fio arched her head back, moaning. Amidst the wonderment burning through her body was a second sensation: her transformation was picking up. Her body was responding to the Ninetales’s attentions in more ways than one, and she shuddered with overstimulation as he continued lapping at her, the sensations filling her with hot arousal and speeding her change along.

Her feet were now long paws capped in three toes; she felt her cheeks burn as they blushed a deep red, sparking with delight. Her long, triangle-tipped ears waggled in the breeze, free from any of her old hair. And to complete the change, a final tug asserted itself at the base of her spine as she painlessly sprouted a tail. Panting from the Ninetales’s attentions, Fio glanced over her shoulder to have her suspicions confirmed: a zigzag shape, brown at the base, with a small heart contour at the end.

She was a Pikachu, now: a cute, female Pikachu who was currently being eaten out by a confident male Ninetales.

The fox pokemon dipped his tongue into her and Fio cried out, her new voice wilder, yet still definitely female. She marked somewhere in the back of her mind that if she had heard such a voice as a trainer, she would have assumed the pokemon in question was in heat.

Heat? Should that worry her? A tiny part of her thought it should, but the twin songs of ecstasy and her still-ongoing wash of tranquil feeling drowned it out.

When the Ninetales lifted his head from her snatch, Fio was shuddering, breathing shallow for sheer arousal. She whined with need, and he smirked, turning to show off his cock: long and slender, but with a formidable knot at the base. His query went unspoken, but she answered anyway:

“Please,” she breathed, squirming for attention. Her pussy burned with unattended heat. “Please, I need it!”

“Very well then,” the Ninetales replied, his voice almost a purr. As if it was second nature, Fio leaned back into the grass, her back against the earth. Gradually the sky was shadowed by his form, for he was far larger than her, now. Angling himself low, he arranged for the tip of his cock to tease as Fio’s entrance, and then—

Her voice hitched and she sang with delight as the Ninetales slid into her. She clenched around him, tongue lolling from her mouth and cheeks sparking errantly as she was rutted by the fox. Any lingering doubts had long since faded, and her world spun with delight as she marveled in his presence. He filled her as she never thought she could be filled, and every thrust, every push, every press forward on his part sent her trembling with joy. Her pokemon pussy squeezed around him again and again, and she was desperate for him to fill her. By now, her heat had spread to encompass her whole body, and she was ecstatic at the fact that this strange creatuer was actually rising to the occasion. He was satiating her heat! And so long as she could continue ascending this peak of pure bliss, Fio found herself completely uncaring towards whatever the consequences might be.

“Good girl,” the Ninetales forced out from behind gritted teeth. “I’ve looked so far for a human girl to fit the role I had in mind… it seems you will do marvelously.” He glanced down at her, a tiny blush burning from behind his pale fur. His voice was strained. “Are you ready for the finale?”

The finale? Fio glanced down at where the two of them met. His knot was holding so deliciously close to her entrance. “Oh, yes,” she breathed.

He didn’t need any more affirmation than that. Surging forward, sinking into her, he barked triumphantly as his knot filled her tunnel and his seed shot into her depths. Fio gasped as her own orgasm rolled over her, her vision haloing from sheer delight as pure ecstasy streamed through her body, following pleasure with pleasure. His knot was spreading her so wide, and yet it felt right—just as the intimate warmth of his seed felt as if it belonged in her belly. Fio hadn’t known it until today, but she wasn’t complete without this—without his cock and his attentions.

She slowly crested down from her orgasmic high, and shuddered as he slipped his knot from her. Some of his seed leaked from her, though less than she would have expected. As she continued to lay there, panting in the grass, she felt his warmth as he cradled his body around her protectively.

Eventually, she rose on faltering legs, still growing used to her new body. “Hop on my back,” the Ninetales told her. “Come.” Fio followed his commands, and he took off racing, racing across hills and past forests and over streams and through high mountain passes.

Though she wasn’t sure, Fio found herself wondering if she was even in the same world they had departed…

When the Ninetales stopped, it was on a hill overlooking a town. Fio gasped at the sight: those bustling about town were all pokemon, creatures of various species going about errands and running shops and living busy lives. There was no human in sight. Some of the pokemon wore bandanas or bows or other accessories, and Pelipper flew overhead, carrying stamped letters and other mail.

“Welcome to a world inhabited only by pokemon,” the Ninetales told her, turning his head to smile at the small Pikachu riding his back. “We have much need of you. I have much need of you.”

Fio wondered what was in store for her in this exciting, unique new world. Whatever it was, it seemed to be worth the change she had undergone—and, she thought, the not entirely unanticipated new heaviness she could feel growing in her belly.

Whatever waited, she was happy to meet it. She smiled down at the pokemon she had lain with. “Show me,” she said.