Knock knock!
"Hello? Is anyone here?"
"The door's open come in!" Professor Oak called from across the lab.
The door creaked open slowly.
Ash turned instinctively toward the sound, curious.
A girl stepped inside a ray of color against the lab's neutral walls.
She had long, flaxen-blonde hair flowing past her shoulders, a black sleeveless top paired with a red mini skirt, and black stockings tucked neatly into her sneakers. A pink hat rested atop her head, casting a soft shadow over her face.
Her features were delicate and lively—cheeks faintly flushed, eyes bright and blue like polished sapphires.
When she spotted Ash, surprise flashed across her expression.
"Ah! Long time no see, Ash!" she said with a joyful smile. Her gaze drifted to his shoulder. "Oh, and you're that little Pichu from back then! You've evolved into Pikachu!"
Ash blinked, taken aback.
Wait, what? Who…?
Pikachu waved cheerfully. "Pika! Pikachu!"
Ash looked down at his partner, completely lost. You know her? How do you know her?!
He frowned, studying the girl's face. Something about her looked familiar… and then it hit him.
"Wait… you're—Serena, right?"
Serena nodded quickly, smiling even wider. "Yep! I thought you didn't remember me!"
"Heh… of course I do! How could I forget?" Ash replied awkwardly, rubbing the back of his head.
Truth be told, he'd almost forgotten.
He'd met Serena years ago—back at Professor Oak's summer camp, when he was six.
At the time, his companion had been a tiny Pichu, not yet evolved.
He and Pichu had found a lost girl crying near the forest path. That girl had been Serena. Ash helped her find her way back to camp—and ever since, she'd come by to play almost every day.
Unlike the other kids, Ash hadn't spent his time gawking at Pokémon. He'd taught Serena what he knew types, battles, and care.
That small act had changed her life. It was the spark that ignited her love for Pokémon.
And before they parted, she'd made him a promise.
"When I start my Pokémon journey, I'll come find you, Ash!"
He'd laughed it off back then.
After all, Kalos and Kanto were worlds apart.
But now, standing before him, was proof that she'd meant every word.
"You've… really grown, Serena," Ash said, trying to sound casual. "You're even more beautiful than I remembered."
Serena froze, her face turning as red as her skirt. "W-Wha—Ash!"
She turned away quickly, flustered. Pikachu snickered softly. "Pika pika~"
In truth, Ash finally understood what had happened.
Professor Sycamore Bratano had contacted Oak recently because of Serena. That was how Oak ended up requesting Froakie from Kalos in the first place.
So this is it, Ash realized. This is the real butterfly effect.
A small act from childhood had rippled across time and space, changing both their destinies.
Since Ash had once promised her, there was no way he could turn her down now.
Besides… traveling with a pretty girl wasn't exactly a bad deal.
Serena was technically ten, but she looked older—around fourteen or fifteen—and carried herself with confidence. Her outfit was stylish yet practical, and her energy filled the room.
Ash couldn't help but smile. This journey's going to be interesting.
A little while later, the two of them stood outside Professor Oak's lab, ready to set off.
"Be careful out there, Ash!" Professor Oak waved from the doorway.
Delia, standing among the gathered villagers, dabbed at her eyes. "Take care, honey! And Serena, dear you look lovely! I'm so happy Ash finally has a travel companion."
Then, in the same breath, she added with a teasing grin, "Ash, I don't mind you having a girlfriend but no grandkids yet! You're only ten!"
Ash froze, face twitching. "Mom!!"
Even Serena blushed crimson, hiding behind her hat. "M-Mrs. Ketchum!"
Pikachu facepalmed. "Pika…"
Too flustered to argue, Ash grabbed Serena's hand and hurried down the road.
"Let's just go already!"
Behind them, Delia waved with a knowing smile. "Take care, you two!"
A few hours later…
"Over there, Fennekin! Finish it with Tackle!"
In a grassy clearing not far from Pallet Town, Serena commanded confidently. Her Fennekin leapt forward, flames flickering from its ears as it lunged at two wild Spearow.
Boom!
Both birds dropped instantly.
Ash blinked, stunned. "Wait… she just took down two at once?!"
Serena turned back with a proud smile, hands on her hips. "Hehe~ I'm awesome, right? This is all thanks to you, Ash!"
"Thanks to me?" he repeated, bewildered.
"Of course!" she said brightly. "You're the one who taught me about Pokémon back at camp. After that, I started training with my mom's Pokémon every day. By the time I got Fennekin, I'd already battled tons!"
Ash stared, speechless.
So that one summer had turned a shy little girl into a confident trainer…
She was supposed to be a performer, he thought. Now she's out here battling like a pro?!
He sighed, half-laughing. "I guess this really is the butterfly effect."
Serena giggled, tucking her hair behind her ear. "Then let's make sure it keeps spreading—in a good way."
Ash grinned. "You got it."
Pikachu and Fennekin exchanged a look, both letting out cheerful cries.
"Pika-chu!"
"Fenne~kin!"
The journey had only just begun—but already, it was clear this was going to be a partnership full of surprises.
(End of Chapter 5)