Chapter 1 Hidden monster
In the far reaches of the East Blue, a young boy—no older than seven—stood at the edge of a peaceful village, gazing calmly at the horizon.
Despite his age, the boy stood at an astonishing **160 cm**, towering above normal children. But in the world of **One Piece**, where giants and monsters walk the seas, his height was merely unusual—nothing impossible.
"Finally… after two years of treasure hunting. This should be enough for my voyage here in the East Blue," he murmured.
The boy's face was soft and tender, almost cotton-like in its gentleness, yet his body was toned and muscular. A **massive serpent** wrapped lazily around his torso, while at his feet rested a turtle—one not ordinary, but the **Three-Tailed Beast, Isobu**.
His name was **Fang**.
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## **His Past Life**
Before waking in this world, Fang had been a young man on Earth—sharp-eyed, elegant, and talented enough to graduate from **Harvard University**. He was a loving brother and part of a beautiful family.
But tragedy struck.
His younger brother fell ill with cancer, and despite spending all their money on treatments and operations, the boy still died.
Fang's world collapsed. He stopped working, stopped caring—eventually getting fired. His family grew worried.
One rainy day, during a planned family vacation, their car skidded off a cliff.
Fang survived. Everyone else didn't.
Broken beyond repair, Fang finally gave up. He jumped from the 20th floor of his apartment building. As the ground rushed toward him, he felt no fear—only relief.
But time suddenly froze.
A glowing man with a white mustache appeared before him.
"I'm giving you a new life," the man said softly. "I failed to protect you."
Fang couldn't speak. A blinding light swallowed him whole.
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## **Rebirth**
He awoke in total darkness—floating. He sensed another presence.
*Ding.*
"Hello, Host. I am your System. I will grant you abilities, pets, weapons, and more—every two years."
"System… where am I?"
"You are in your mother's womb. You will be born as the **twin brother of Monkey D. Luffy**."
"So I really got reborn…" Fang thought, excitement surging through him. A new life. A new world.
"Host, I can place your body on autopilot. You may open your eyes at age two."
"Do it," Fang replied. Sleeping through infancy sounded much better than waiting years to train.
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## **Age 2**
Two years later, a small child with soft black hair and smooth, tender skin opened his eyes for the first time.
Through his blurry vision, he saw a vast ocean and a man wearing a green cloak speaking to a crying woman.
"Please… this is the only way to protect them," the man pleaded.
The woman wiped her tears, nodded silently, and boarded another vessel.
Fang's young heart tightened. *Is that… my mother?*
The baby reached toward her and cried desperately. He could still hear her sobs fading across the waves.
The cloaked man hurried over, lifted him gently, and whispered with trembling lips:
"Fang… protect your brother. I can't… I-I'm… sorry…"
As Fang stared at the man's face, he finally understood—
The woman leaving on the other ship was **Luffy's—and his—mother**.
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## **Age 3 to 7**
Fang grew quickly. By age three, he had begun to work out under the System's guidance.
Every two years, his System rewarded him:
**Year 2 Reward:**
* *Devil Fruit:* **Dog-Dog Fruit, Mythical Zoan: Fenrir**
**Year 4 Reward:**
* *Pet:* **Isobu, the Three-Tails**, size adjustable
**Year 6 Reward:**
* *Pet:* **Jörmungandr**, the World-Serpent, mortal enemy of Thor, size adjustable
Five years of rigorous training passed, followed by two years of exploring the deepest trenches of the sea. Now, at age seven, Fang finally returned to **Windmill Village**—to Luffy.
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## **Windmill Village Tavern**
Laughter filled Makino's tavern.
"Hey Shanks! Take me on your next voyage! I wanna be a pirate too!" Luffy demanded.
"You're too young," Shanks chuckled.
"I'm strong! My punch is like a pistol!" Luffy declared proudly.
Yasopp grinned. "You're the same age as my son. Too young for the sea, kid!"
"I'm not a kid!"
"Alright, alright. Drink some juice," Shanks said.
Luffy drank it instantly.
"See? Still a kid," the crew laughed. Even a girl with white and red hair—**Uta**—laughed along.
"Hmph! When my brother comes back, he'll beat all of you!" Luffy declared.
Everyone went silent. None of them knew Luffy had a brother.
At that moment, the tavern doors slammed open.
A group of bandits entered.
"Don't worry, boss lady. Just give us ten barrels of wine," a lackey said.
"We ran out…" Makino trembled.
"So what are these guys drinking? Water?" the bandit boss sneered.
Shanks calmly offered a bottle. The bandit slapped it away, smashing it.
As he lifted his blade again—
A **hand** stopped it.
A quiet voice followed:
"If you hurt my little brother… I'll kill you."
The bandit's lackeys scattered in terror. The boss froze as Fang's grip tightened. A small cut appeared on his neck before he collapsed and crawled out of the tavern.
"BROTHER!!!" Luffy threw himself at Fang, hugging him tightly.
"You're seven already… can you stop ambushing me every time I come back?" Fang grumbled, peeling him off.
"Hey, who's that snake?" Luffy asked, pointing at Jörmungandr.
"She's Jörmungandr. Found her while traveling."
Shanks felt a chill—even in her small form, the snake radiated overwhelming power.
"Isobu! Jörmungandr! Let's play!!" Luffy shouted.
The turtle and serpent happily followed him.
Fang turned when he heard a small voice.
"Hey… who are you?"
A girl with white and red hair—Uta—stared up at him.
"I'm Luffy's twin brother. Why?"
Everyone in the tavern froze.
The difference between the two brothers… was unbelievable.
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