The boy awoke to the scent of salt and the sound of waves crashing against wood.
He jolted upright, coughing, his clothes soaked and clinging to him. His breath came in ragged gulps, heart pounding as if it had just restarted after a long pause. He looked around, confused—he was lying on a makeshift raft, barely more than tied logs and shredded sailcloth. Above him, the sky stretched vast and empty, a canvas of blue so endless it hurt to look at.
The sea rocked him gently, almost mockingly.
Then the memories hit.
Not of the ocean. Of another world.
The screech of tires. The flash of headlights. Pain, then nothingness.
And yet… here he was. Alive.
"What… the hell?" he whispered, touching his chest. No wounds. No scars. But this body—it felt lighter, leaner. Younger. He staggered to his feet on the unsteady raft, realizing his limbs were smaller, his height diminished.
He caught his reflection in the water.
A boy. No older than fifteen. Hair tousled, eyes wide with panic and wonder.
That's not me, he thought.
Or maybe it was now.
As the panic rose, his hand brushed against something smooth and round beside him. It was sitting on a bundle of cloth—an odd-looking fruit with swirling patterns etched into its flesh, the color of iron with silver veins.
"No way…" he breathed.
He recognized it from years of fiction, from anime marathons and fan theories. The swirls, the size, the aura of strange power—it could only be one thing.
A Devil Fruit.
His heart thundered. This had to be a dream. Or some kind of delusion. Or maybe—
"This is the world of One Piece," he whispered aloud, a chill running down his spine.
His mind reeled. How? Why? Why him? He hadn't been anyone special. Just a kid who loved strategy games, mythology, and occasionally wondered what it would be like to have powers.
Was this reincarnation? Isekai?
His stomach growled violently, reminding him that whether dream or not, he was still very much hungry. Without thinking, he reached down, grabbed the fruit, and took a bite.
It was the worst thing he'd ever tasted.
Like rotten iron and week-old cabbage dipped in vinegar. He gagged, nearly spitting it out—but he forced himself to chew and swallow.
"I already know what happens if you eat half..." he muttered, remembering the rules. "No sharing Devil Fruits."
He dropped the half-eaten fruit, letting it roll off the raft and into the sea with a soft plop.
Instantly, a strange warmth coiled through his chest. Not painful—just alien. Like something ancient and intelligent now stirred within him.
"What power did I just eat?"
No voice answered. But a word floated into his mind, unbidden:
Kōtai.
Swap.
He stared at his hands.
Something had changed. But he didn't know what yet.
Suddenly, the calm ocean shifted. The raft jerked hard as a wave slammed into it. On the horizon, a ship appeared. Small, fast, and flying a Jolly Roger he didn't recognize.
A pirate crew.
He dropped flat, hoping they wouldn't notice him. No such luck.
"Hey! Looks like a castaway!" someone shouted from the ship.
A moment later, a rope was tossed down. With no real alternative, he grabbed it.
Pulled aboard, he found himself face to face with a dozen rough-looking men—pirates, definitely. Scarred, grinning, half-drunk on cheap rum. At their front was a tall, bald man with a tattoo of a compass on his scalp.
"You got guts, kid," the captain said, voice like gravel. "What's your name?"
He hesitated. His real name felt… wrong now. Like it belonged to another life. Another world.
So he gave the first thing that came to mind.
"Kairos."
The captain laughed. "Greek, huh? Means 'right moment,' doesn't it?"
Kairos nodded. The man clapped him on the shoulder.
"Then you'd better pray this is your right moment, kid. Welcome aboard the Rust Fangs."
---
That night, Kairos lay on a hammock in the ship's hold, staring up at the ceiling.
His stomach was full for the first time in this new life. But his mind was spinning. He had eaten a Devil Fruit—he was sure of it. But he didn't know what it did yet.
Kōtai… Swap…
Swap what?
He raised his hand and looked at it, then glanced at the sleeping pirate snoring beside him. Just as a test, Kairos reached out and touched the man's arm.
A weird pulse went through him—like tugging something invisible.
The pirate jerked awake, confused. "Wh-what the hell? Why do I feel… weak?"
Kairos blinked. He didn't feel any different… except—
He curled his fingers into a fist. His muscles felt tighter. Stronger. He punched the wooden support next to him—and splinters flew.
"No way..."
He looked at his hand again, awe settling in. "I swapped our strength."
Then, just as quickly as it came, the power faded. His body slumped back to its normal state.
And in his mind, a timer ticked down.
30 seconds of swap. Cooldown: 1 minute.
The Kōtai Kōtai no Mi… he realized. The Swap-Swap Fruit.
It didn't feel like much. Not yet. But deep in his gut, Kairos knew:
This fruit would either kill him in this chaotic world—or it would turn him into a devil the world would never forget.
Either way…
his pirate story had begun.