The Grand Line was an unpredictable sea of monsters, pirates, and chaos—an eternal battlefield where the world's strongest rose and fell like waves in a storm. And yet, amid the madness and tyranny of the World Government, there were rare sanctuaries—places untouched by the Marines, ignored by pirates, and hidden from the claws of the Celestial Dragons. One such place was Kaien Island, a small, crescent-shaped jewel surrounded by jagged reefs and whispering winds.
Kaien Island was not a place known for its size or trade, but for its legacy. A towering stone wall—smooth, unyielding, and weathered by centuries of storms—wrapped around the settlement at the island's heart. Beyond that wall lay a world frozen in time, where wooden houses with curved, tiled roofs stood like monuments to an era long past. Their architecture was ancient, each beam and panel carved with stories of generations who lived by the blade and perished by it. Lanterns hung from the eaves, their soft glow dancing across stone-paved courtyards during the quiet nights.
At the very center of the compound stood the Kaien Clan Pavilion, a sprawling four-story estate that dwarfed every other structure on the island. It was not just a home—it was a fortress, a library of knowledge, and a temple of martial philosophy. The walls inside were lined with scrolls, each containing a martial art or sword style preserved for centuries. There were thousands of them, spanning cultures and philosophies—arts designed for elegance, destruction, assassination, or defense. The Kaien Clan had not merely mastered these arts—they had perfected and evolved them, pushing each style beyond its original limits.
The Kaien Clan was unlike any other in the world. They were not pirates, nor Marines, nor bounty hunters. They were keepers of the fist and blade, inheritors of a philosophy that valued growth through battle and wisdom through refinement. The clan believed that no art was ever truly complete; every form could be broken down, analyzed, and reconstructed into something stronger, faster, deadlier.
Their name was whispered in taverns and feared even among pirates. The clan's leader, Makuro Kaien, had cemented that reputation himself. It was said that Makuro once crossed blades with Dracule Mihawk, the World's Greatest Swordsman, on an uninhabited island in the New World. No one knew who had truly won that duel—both men had walked away alive, which in itself was a testament to Makuro's terrifying skill. Though Mihawk's title remained, it was said that Makuro's sword could rival the "Yoru" itself.
Yet Makuro Kaien was not a man who sought fame or glory. He ruled the clan with a heavy, unyielding hand. His voice alone could silence a courtyard full of warriors. His towering frame—broad-shouldered and carved like stone—made even seasoned fighters lower their heads. He carried himself like a storm contained within a man, radiating an aura so oppressive that few dared look him in the eye for too long. His presence demanded respect not because of fear alone, but because of the raw, unwavering confidence that clung to him like a second skin.
The Heir of the Blade
Yet, for all Makuro's might, the pride of the clan was not the man himself, but his only son—Lucan D. Kaien.
Lucan was a boy of sixteen, but he carried himself with a weight and sharpness far beyond his years. His hair was jet black, like most of his clan, but streaked with faint purple highlights that gleamed when sunlight struck them, a strange mutation that made him stand out even among his kin. His eyes were sharp and dark, almost predatory, with a glimmer that suggested both intelligence and arrogance. His features were striking—high cheekbones, a defined jaw, and a faint smirk that always seemed to curl his lips, as if the world around him was nothing but a challenge waiting to be conquered.
His body was lean yet sculpted with muscle—proof of years of relentless training. Every scar, every hardened callus on his hands told a story of discipline and obsession. Even at a glance, one could tell Lucan Kaien was not just another swordsman. There was a precision in his movements, a fluidity that made him look less like a boy training and more like an artist painting with steel.
Lucan lived for martial arts. To him, swordsmanship was not merely a tool for survival or a weapon for killing—it was a language. He spoke it fluently, obsessed with breaking down every form, analyzing every movement, and finding ways to improve. He was the type to watch a single swing for hours, memorizing the angle, the momentum, the shift of weight, and then repeat it a thousand times until it became as natural as breathing.
"Nothing is perfect," Lucan often muttered under his breath while training. "If it were, there'd be no reason to fight. Perfection is the death of growth."
That day, Lucan stood in the main courtyard of the clan pavilion, stripped down to his training garb—a loose, sleeveless black martial robe tied with a red sash. The morning sun bathed his tan skin, glistening with sweat from hours of practice. In his hands was a training sword, but it was no ordinary weapon. Forged from a dense alloy the clan used for conditioning, the blade was dull and heavy, weighing over sixty pounds.
Every swing was an ordeal, yet Lucan moved with a grace that defied the sword's weight. He was practicing "Mizu Nagare", the Flowing Water style—a sword art designed not to kill, but to disarm, disable, and control. The style was all about precision and adaptability, using minimal force to redirect attacks while maintaining dominance over an opponent's movements. It was said that a true master of Flowing Water could defeat ten swordsmen without killing a single one, simply by breaking their rhythm and stealing their control.
But Lucan was not satisfied. His movements were sharp, but not sharp enough. His transitions were smooth, but not flawless. Each swing left him with a lingering irritation, as if he were on the verge of grasping something greater yet couldn't quite reach it.
"Too rigid," he muttered after a misstep, adjusting his stance. He repeated the sequence again—spin, step, sweep, redirect.
From the high balcony of the pavilion, Makuro Kaien watched his son with a complex gaze. His massive arms were crossed, and the faintest ghost of a smile tugged at his lips.
"He's improving again," Makuro said to no one, his deep voice rumbling like distant thunder. "His mother would've been proud."
But as quickly as the smile appeared, it vanished. His jaw tightened, and a shadow fell over his expression. His mind wandered—not to Lucan's progress, but to the world outside their walls. A world he despised. A world that had taken far too much from him already.
Makuro's hands clenched into fists, the scars on his knuckles paling against his dark skin. The World Nobles. Even the thought of them filled him with venom. They had killed his wife, Lucan's mother, years ago under the guise of "justice." Their greed for the Kaien Clan's martial arts had not lessened with time. They wanted the clan's scrolls—the centuries of knowledge that could rival even the greatest weapons in the world. And they would stop at nothing to obtain it.
"Damn them," Makuro growled, his voice low and dangerous.
The Arrival of News
That morning, Makuro had received word. A Marine Admiral was coming. Not a vice admiral, not a fleet commander—an Admiral, the fist of the World Government, was personally setting foot on Kaien Island. Makuro knew what that meant. This was no "peaceful visit." It was a warning.
Makuro turned his gaze back to Lucan, who was still lost in the rhythm of his swings. There was something different about his son—something raw and unshakable. The boy was not just a prodigy; he was a force waiting to be unleashed.
Makuro descended from the balcony, his heavy footsteps echoing against the wooden stairs. By the time he reached the courtyard, Lucan was still practicing, so focused that he didn't even notice his father's presence.
"Lucan," Makuro said, his voice sharp.
Lucan stopped mid-swing, breathing heavily, sweat dripping down his brow. He grinned. "Ah! Dad. You scared me. I didn't even hear you coming."
Makuro raised an eyebrow. "That's because you were too focused on the wrong thing."
Lucan blinked. "Wrong thing?"
"You're chasing speed and precision, but you've forgotten awareness," Makuro said, stepping closer. "A true swordsman's mind must be as sharp as his blade."
Lucan sighed. "Always the lecture. But… I guess you're right." He chuckled. "So, what's with all the tension today? Everyone's on edge. I can feel it."
Makuro's expression darkened slightly. "The Marines are coming."
Lucan froze. His grip on the heavy training sword tightened. "Marines? Here? Why?"
"They claim it's a 'visit,'" Makuro said, though his tone made it clear he didn't believe that for a second. "But I suspect they want something. And they'll push until they get it."
Lucan's jaw tightened. He had no love for the Marines. He'd heard the stories—the bribes, the false justice, the atrocities committed in the name of order. But for him and his father, the hatred was personal. The Marines had allowed the World Nobles to commit atrocities against the Kaien Clan. It was a wound that had never healed.
Lucan leaned the heavy training sword against his shoulder, his breathing still ragged from practice. The mention of the Marines had drained the relaxed grin from his face. Now his dark eyes gleamed with something sharper—resentment.
"They're not here for a friendly visit," Lucan said, his tone firm. "The World Government doesn't send admirals to drink tea and chat. What do they want this time?"
Makuro studied his son for a long moment. Lucan's intuition was unnervingly sharp, almost to the point of arrogance. But Makuro knew better than to treat it as simple pride. Lucan had inherited his mother's instincts, a piercing ability to see through lies and read intentions. It was a trait that had kept her alive through countless battles—until the day the World Nobles decided her existence was inconvenient.
Makuro's jaw tightened at the memory, but he pushed it aside. "The same thing they've always wanted," he finally answered. "Our scrolls. Our secrets. They see our arts as dangerous—because they are. But they want that power for themselves, and they'll cloak their greed under the excuse of 'maintaining balance.'"
Lucan's expression hardened. "Then why let them come at all? Why not—"
"Because this world isn't so simple," Makuro cut in, his voice heavy with authority. "We've survived this long because we've chosen our battles. A single mistake against the wrong enemy can destroy everything—our clan, our island, everything we've built."
Lucan hated that logic, but he understood it. The Kaien Clan's isolation wasn't weakness; it was strategy. They had no interest in ruling the seas or challenging the Yonko or Marines. Their art was for themselves. But the World Government saw power it couldn't control as a threat—and threats were meant to be eliminated.
Makuro Kaien towered over his son as they stood in the courtyard. He was a giant of a man, nearly seven feet tall, with a physique that seemed carved from dark granite. His black hair was streaked with silver at the temples, tied back in a rough tail that barely restrained its wildness. His face bore the marks of countless battles—thin scars across his jaw and brow, each a memory of survival. Yet despite his rugged appearance, his presence was refined, commanding, and unshakable.
Makuro's voice rumbled like distant thunder. "You've been training hard, Lucan. Too hard, maybe. You're driven by something… but what? Is it strength? Is it revenge? Or is it something else entirely?"
Lucan smirked, though sweat still dripped from his brow. "Strength. Always strength. But not for the sake of revenge. I want to be… unstoppable. To master everything. Every technique, every form. To understand them so completely I can break them apart and rebuild them better."
Makuro studied him, his sharp eyes narrowing. He saw both promise and danger in those words. Lucan's talent was undeniable, but talent without humility was like a blade without a sheath—beautiful, but dangerous even to the one who wielded it.
"You sound like me when I was your age," Makuro said at last. "The difference is, I learned humility when I lost my first duel against a pirate worth nothing but his blade. Pain and failure teach faster than any scroll."
Lucan tilted his head. "Then maybe I need to taste that too, huh?"
Makuro's lips curled into a small, proud smirk. "Perhaps."
The Kaien Clan's compound bustled with quiet energy as word spread of the Marines' impending arrival. Warriors trained in the courtyards, their movements sharp but tense. Servants swept the stone pathways, whispering nervously about what an admiral's visit might mean.
The clan itself was a mixture of tradition and lethality. Men and women alike were trained in martial arts from the time they could walk, mastering both unarmed combat and weapons. Every member of the clan understood at least three distinct styles by adulthood, whether they preferred the elegance of the Flowing Water style or the brutal precision of the Iron Fang style.
The walls of the central estate were lined with scrolls written in ink so old that the characters seemed alive, etched into the fibers of the paper with the intensity of the masters who had created them. There were scrolls on everything—stances, techniques, pressure-point strikes, energy manipulation, and philosophies of combat.
Lucan had read them all. Every single one. Not just read, but studied, dissected, and reimagined. He saw weaknesses in even the most revered forms, tweaking angles, altering footwork, experimenting with timing and breathing. If martial arts were a language, Lucan wasn't just a fluent speaker—he was a poet rewriting its grammar.
By late afternoon, the sea winds had changed. A distant horn echoed across the horizon, carried on the salty air. Lucan, who had been washing up and changing into a clean black robe, heard the sound and immediately felt a chill crawl up his spine.
"They're here," he said to himself, stepping out onto the balcony of his room on the third floor. From there, he could see beyond the wall, out to the churning sea. And on that sea, like black teeth cutting through the waves, was the Marine fleet.
At the head of the fleet was a massive warship, its sails bearing the symbol of the Marines—a seagull perched over a stylized wave. Even from this distance, Lucan could feel the oppressive presence emanating from it. This wasn't just any Marine ship. This was an Admiral's ship.
Inside the great hall of the pavilion, Makuro stood with a handful of the clan's senior members. His hand rested casually on the hilt of his sword—a blade that had cut down warlords, beasts, and men foolish enough to challenge him. The blade's scabbard was plain, almost humble, but the aura it gave off was unmistakable.
"They send an admiral," Makuro said, his tone flat but dangerous. "Not a negotiator. Not a vice admiral. An admiral."
The elders shifted uneasily. They all knew what this meant. Admirals didn't negotiate—they demanded. They didn't request—they took.
"They'll want the scrolls," said one of the elders, an old woman with white hair and sharp, hawk-like eyes. "They always do. And if we refuse, they'll burn us out of history."
Makuro's gaze hardened. "Then let them try."
The room fell silent. Everyone present knew what Makuro Kaien was capable of, but even he was not invincible. An admiral was a force of nature—a single man with the power of entire fleets.
"Prepare the gates," Makuro ordered. "We'll receive them with respect. But if they step too far…" His voice dropped to a cold, unspoken threat. "They'll regret setting foot on this island."
Lucan joined his father in the courtyard moments later, dressed in his clan's formal garb—a black robe embroidered with silver threads that shimmered like moonlight. Though younger and slimmer than his father, he carried himself with the same unshakable confidence.
"Dad," Lucan said, glancing at the horizon where the Marine fleet crept closer. "If they want a fight, I want in."
Makuro gave him a hard look. "You're not ready."
Lucan smirked. "I'll be ready when I choose to be."
Makuro almost smiled. Almost. The boy's arrogance was infuriating—and yet, it reminded him so much of himself that he couldn't help but feel proud.
By sunset, the Marines had reached the island's shores. The sound of drums echoed as the massive admiral's ship dropped anchor just beyond the reef. Smaller boats were lowered, ferrying Marines in crisp white uniforms to the sandy beach. The air was thick with tension.
From atop the wall, Lucan watched them approach, his hand twitching at his side, itching for a blade.
At the front of the landing party, a figure walked with calm, deliberate steps. He was tall and broad, with a white Marine coat draped over his shoulders like a cape. His face was partially hidden beneath the shadow of his Justice cap, but even at a distance, Lucan could feel the weight of his presence.
"That's him," Makuro said, stepping up beside his son. His deep voice was low, but it carried an edge of steel. "An admiral."
The man's boots sank slightly into the sand as he stopped at the water's edge, looking up at the imposing wall of the Kaien compound. His gaze was sharp, cold, and unrelenting—a predator's gaze.
Then, with a voice that carried across the shore and into the hearts of everyone listening, he spoke:
"I am Admiral BAkainu Sakazukiby order of the World Government, I request entry to the Kaien Clan."