"Hoo! Hoo!"
"Thirty nine thousand, two hundred and twenty-one!"
"Thirty nine thousand, two hundred and twenty-two!"
By the sea, a sturdy boy of about seventeen or eighteen years old was holding a dumbbell ten times his size, swinging it with all his might.
Each swing sent gusts of wind rushing through the air.
He had been at it for most of the day, sweat dripping down his sharp muscles onto the ground.
At 1.9 meters tall with a powerful frame, it was hard to believe he was just a teenager.
"Forty thousand!"
Bump!
At the final swing, his arms gave out and the massive dumbbell crashed to the ground.
"Hah! I'm exhausted!" he gasped, collapsing onto the sand.
His arms trembled from the effort.
"Three thousand more swings than yesterday!" he said, clenching his fists with excitement.
You have to understand, this dumbbell weighed a hundred tons, yet he could swing it tens of thousands of times with ease.
He wasn't just an ordinary boy.
He had traveled to a world where strength was everything.
And this world was familiar to him.
It was the world of One Piece, the anime he had loved as a child in his previous life.
Only, he had arrived early.
At just ten years old, he had stumbled across a newspaper article about the Rocks Pirates.
The current year was 1480, forty years before Luffy even set sail.
Kairo was stunned by the news.
Anyone who knew One Piece understood this world was ruthless and full of danger.
Pirates would come, maybe even invade someday.
Though there were fewer pirates now than in later generations, Kairo knew trouble was inevitable.
What shook him even more was realizing he was in the New World, the second half of the Grand Line.
Transmigrating in a ten-years-old boy was already overwhelming.
Now, in this dangerous era, Kairo felt a deep sense of crisis.
But after a moment of panic, he composed himself.
In his previous life, he had been a mercenary, a strange as it's sound, he decided to accept this reality.
How did he become a mercenary?
Well, he once heard that working as a mercenary in the Middle East during summer could be lucrative.
After a friend's recommendation, he had joined a mercenary group without much thought.
Thus began his odd career.
As the saying goes, if you often walk by the river, you're bound to get your shoes wet.
During one battle against an opponent nicknamed Blake Hunter, a melon sized grenade suddenly appeared beside him.
He had no idea who threw it.
The explosion was instantaneous.
Before Kairo could react, his body was torn apart and darkness claimed him.
After waking up in this world, Kairo found himself in the body of a 10 year's old boy.
The original owner had been unlucky, caught by rough waves while fishing near the shore, he was slammed against the rocks and knocked unconscious.
It was a case of the dove occupying the magpie's nest.
The island Kairo was on was small, home to just over a thousand people, a modest town located in the first half of the New World. Pirates were rare here, as the nearby Navy G-8 base kept the area secure.
Although this wasn't the same G-8 base later generations would come to know, it gave 10 year's old Kairo a sense of safety.
Once his surroundings became clear, Kairo began to recall memories of watching One Piece in his past life.
What surprised him was how vivid those memories were.
Despite having watched One Piece since childhood, his mercenary lifestyle had left little time for leisure, and most of the story had faded from his mind, until now.
This sudden clarity filled Kairo with excitement.
With some of those memories intact, he knew he could make it to the very end of this world's story.
But Kairo wasn't content with just surviving, he wanted to carve out a legacy here.
Settling for the status quo wasn't his style.
In this life, his name was Kairo Stoneheart.
After confirming that he was truly in the world of One Piece, Kairo began to plan his training regimen.
He knew this world was dangerous, especially in the Age of Great Navigation, when pirates roamed the seas like swarming ants.
He didn't want to die aimlessly.
Determined to live a remarkable life, Kairo set out to train himself.
He knew the power systems here: Swordsmanship, The Three Paths of Haki, Devil Fruits, Spear Techniques...
Anything could make someone stronger.
As a former mercenary, spear skills came naturally to him, but he didn't even have a gun, and the firearms here were flintlocks, which instantly ruled out that option.
What about Devil Fruits?
Kairo dismissed the idea right away.
Did the original owner leave him any Devil Fruit? And even if so, where would he find one?
The Three Paths of Haki was tempting.
There were Three Types:
Armament Haki
Observation Haki
Conqueror's Haki
But with only a ten-years-old's body, he lacked the physical foundation for Armament Haki.
Observation Haki required intuition and awareness.
Conqueror's Hakiwas rare, one in a million chance, and Kairo wasn't sure if he had the potential.
With those three options crossed off, that left swordsmanship and physical training.
He had some knowledge of both, and decided to start there.
His first priority was to train his body, starting with gymnastics.
He took inspiration from Zoro: The anime showed how Zoro trained.
Lower body explosive strength: heavy squats and jumps.
Upper body strength: swinging heavy dumbbells with both hands.
And much more...
Combined with physical training methods from his mercenary days, Kairo knew this plan was workable.
As for swordsmanship, he didn't have any specific skills yet, but he believed that consistent practice would pay off.
Zoro's example gave Kairo the motivation to push forward.
He refused to believe that being a time traveler was all he had going for him.
With this mindset, Kairo stayed in his humble thatched cottage for two days to recover, then began his training.
He was surprised by how fast his injuries healed, within two days, he was back on his feet, strong and ready.
When he had been rescued from the shore, several of his bones were broken.
Yet after a few hearty meals of meat, his body seemed to recover miraculously.
Others didn't find this unusual, it was normal here.
And Kairo now understood what kind of meat he had been eating.
It was from a Sea King, the very creature that bit off Shanks' left arm in the early One Piece story.
This inspired his another idea: perhaps eating such powerful meat could be another path to strength.