One Piece World.
A small boat slowly sailed across the azure sea, a gentle breeze carrying a fresh oceanic scent.
In the distance, the sky met the sea, and white seagulls circled in the air, their crisp calls occasionally echoing.
"Hoo~!!!"
"Haa~!!!"
"Ha~!!!"
Kai practiced the Seventy-Two Forms of Body Tempering on the small deck of the boat.
He performed a unique breathing technique with each posture, emitting special breathing sounds.
Every movement brought Kai soul-piercing pain, as the anti-human movements, combined with the special breathing technique,
made his entire body resemble a boiled shrimp, completely red and steaming hot.
Although Kai's physical strength was now many times greater than when he first woke up,
transforming from a frail teenager into one with distinct muscle lines,
his body still couldn't withstand too much exertion. The body-tempering method, created based on his past life's experience,
could only be practiced up to the ninth form before becoming unsustainable. This was also because Kai possessed the will of a martial arts grandmaster, far surpassing ordinary people.
If it were an ordinary person, they would break their bones and tear their tendons before completing even a single movement.
"Hoo~~~"
Kai performed forms one to nine several times in a row, finally reaching his limit. He took a deep breath and slowly concluded his practice.
He then saw Luffy and Zoro staring blankly at him.
"Amazing! Kai, what kind of move is that? Can you teach me?"
Luffy exclaimed, looking at Kai.
"Luffy!"
Zoro, standing nearby, frowned and reminded Luffy not to pry into other people's cultivation secrets. Casually inquiring about someone else's cultivation method was a major taboo.
Kai had noticed them as soon as they emerged from the cabin, but he hadn't stopped his practice.
His Seventy-Two Forms of Body Tempering were created based on his own physical condition, combined with his rich martial arts experience from his previous life.
It was a body-tempering technique that integrated strength, flexibility, and breathing rhythm. Each movement contained profound martial arts principles.
Just looking at the surface postures wouldn't reveal anything; blindly imitating them would only harm one's body.
"Of course, but this was created based on my own physical condition."
"If you want to learn, I'll have to feel your bones and then teach you a body-tempering method suitable for yourselves!"
Kai didn't refuse Luffy; he even intended to customize a body-tempering technique for them based on their physical conditions.
After a day or two of getting to know them on the ship, Kai discovered that Luffy was a cheerful and passionate teenager, and Zoro was a swordsman with his own unwavering resolve.
Both were promising individuals, and Kai wasn't averse to training them.
"Really? I get a share too?"
When Zoro heard Kai say "them," he knew it included him.
After a day or two of interaction, Zoro had already realized that Kai was no ordinary person.
Especially with the special body-refining technique he practiced, Zoro could clearly feel Kai's physical strength and power rapidly increasing through that method.
Zoro knew perfectly well what rapidly increasing physical strength meant for a swordsman.
Hearing that Kai intended to teach Luffy and himself, Zoro was both shocked and ecstatic.
"What's with the chatter? Who's first?" Kai waved his hand, urging them to hurry up.
For Kai, time was money. Now was not the time for complacency.
He had to seize every moment to become stronger, and then truly experience this different world.
"I'll go first!!!"
Luffy roared, stretching out his arms and pouncing over.
Then, amidst Luffy's pained groans, Kai thoroughly examined his entire body. Every bone and muscle of Luffy's was clear to Kai.
"Now I'll teach you the postures suitable for your body. You can't use your rubber body, or it won't be effective!"
Kai knew Luffy was a rubber man, so he specifically instructed him.
He then demonstrated several postures that Luffy's current body could withstand, along with different breathing techniques.
Amidst Luffy's agonizing screams, crying out for his parents, he performed the exercises a full seven times before finally remembering the six postures and breathing techniques.
"What are you two arguing about!!!"
"Can't a person get some sleep!!!"
Nami's exasperated voice came from the cabin. She hadn't slept enough and was woken by Luffy's screams.
Immediately after, Nami, who had just emerged from the cabin, saw Kai making Luffy perform one special posture after another on the deck.
And Luffy was emitting special breathing sounds and screams, his entire body red and steaming. Her heart instantly sank.
"They..."
"What are they playing?"
"They can't be perverts, can they? What kind of people have I encountered?!"
Nami felt despair at the sight before her, thinking she had encountered perverts.
Fortunately, Zoro, standing nearby, explained the situation to Nami.
"Hoo~~~"
Luffy slowly exhaled, and his red body gradually returned to normal.
"Amazing!!!"
"I feel my strength slowly increasing, and my physical strength has also gotten a bit stronger!"
Luffy carefully felt his body. The immediate effect made him jump up excitedly.
"Grumble~"
A thunderous grumble echoed from Luffy's stomach. Having expended a large amount of energy, Luffy's stomach rumbled.
"So hungry!!!"
"I want to eat meat!"
Luffy clutched his stomach and plopped down on the deck.
"After practicing this body-tempering method, you need to replenish your energy promptly. Eat and then continue practicing!"
Kai lifted Luffy up and tossed him towards a wooden barrel full of apples, telling him to eat them.
"I want to eat meat!!!"
Luffy ferociously devoured several large apples and roared towards the sky.
"Zoro, it's your turn!"
"Oh!!!"
The impatient Zoro responded, leaping directly in front of Kai.
Zoro knew that his greatest opportunity to become the world's strongest swordsman had arrived!
Zoro performed better than Luffy. With the same six postures, Zoro learned the breathing technique in just three repetitions.
Then, sustained by his powerful will, Zoro performed the exercises a full nine times before collapsing exhausted onto the deck.
"My body is slowly getting stronger!"
"Strength! It's also continuously flowing out!!!"
At this moment, Zoro had reached the limit of what his body could endure. He didn't even have the strength to move his thumb.
But he could clearly feel his body getting stronger little by little, and new strength continuously pouring out.
Zoro knew he had encountered a great opportunity. This body-tempering method, perfectly suited for his body, was a priceless treasure.
"Eat!"
Kai saw the exhausted Zoro, a hint of admiration flashing in his eyes.
He put an apple into Zoro's mouth.
"Thank you!" Zoro sincerely thanked Kai, deeply remembering his kindness.
"Practice well. This is just the beginning; the later techniques will be harder and more painful!"
Kai patted Zoro's shoulder, already planning to thoroughly train this resilient, determined, and rigorously self-disciplined young man.
"Just bring it on!" Zoro responded with fighting spirit.
"If only there was meat! Then I could recover quickly and speed up my practice!"
Kai sighed inwardly, regretting not getting some meat on the ship before they set off, which now meant they could only eat apples, affecting their training progress.
"Eh? What's wrong, Nami? Do you want to learn too?"
Kai asked, looking at Nami, who seemed lost in thought.
"Hmph, no way!"
Nami turned her head and walked into the cabin, her slender legs moving gracefully.