A depth of ten thousand meters below the sea surface is no place for ordinary humans. It is a realm where sunlight fades, replaced by darkness and water pressure capable of crushing bones in a matter of seconds.
Yet, amid the silence of that oceanic abyss, a giant resin bubble glides slowly downward. Inside it, a Navy warship bearing the blue seagull emblem cuts through the currents.
On the ship's deck, the soldiers who had followed Rear Admiral Red Eye all the way from the Western Sea stood tense, swallowing hard.
Their eyes widened as they stared at the shadows swimming past their ship.
The Sea King, a colossal fish hundreds to thousands of meters long, glided serenely in the distance; its glowing eyes resembled ghostly lanterns in the dead of night.
Quentin Seven stood at the bow, gazing straight down. His dark eyes reflected the dim light from the seafloor that was beginning to come into view.
"We'll be there soon," Seven said calmly.
In the distance, a massive double-layered bubble emitted a brilliant light, illuminating the dark seafloor.
Fishman Island.
However, before the warship could approach the entrance, a brutal scene unfolded outside the island's main bubble.
A pirate ship had just exploded. Its protective bubble was torn apart, causing seawater to instantly crush the hull and sink the entire crew.
Amidst the whirlpool, a giant figure with thick, fiery-red hair floated, a trident in hand. He rode a massive whale, his chest rising and falling as he regulated his breath.
The Great Sea Knight of the Ryugu Kingdom, Prince Neptune.
Neptune turned his head; his sharp eyes immediately locked onto the silhouette of the approaching Navy warship. The giant merman's jaw tightened.
He gripped his trident tighter. He knew all too well the long history between his race and humanity. The Navy was indeed part of the World Government, but they always turned a blind eye when pirates and slave traders kidnapped his people.
For Neptune, the arrival of this warship was not a good sign.
From the deck, Seven sensed the watchful and intimidating gaze emanating from the Sea Knight. He did not respond with hostility.
Instead, the corners of Seven's lips merely curled into a faint smile. She raised her left hand, signaling the helmsman to ignore Neptune and continue sailing into the official harbor of Fish-Man Island.
Seeing that the Navy ship showed no intention of attacking, Neptune lowered her trident slightly, but her eyes remained fixed on the ship until its hull passed through the bubble membrane of Fish-Man Island.
As soon as the ship docked at the harbor pier, the air and gravity returned to normal.
The Navy soldiers, setting foot in this legendary place for the first time, immediately scattered across the deck. Their eyes—especially those of the male soldiers—instantly turned into hearts upon seeing a group of beautiful mermaids walking around the harbor with cheerful laughter.
"Divide the troops into two groups," Seven ordered, his voice cutting through the soldiers' cheers. "One team handles logistics and the ship's refueling. The second team, follow Sakazuki and Borsalino."
"Where are we going, Brother?" Borsalino adjusted his round glasses, his eyes casually sweeping over the island's beauty.
"Exploring," Seven replied briefly. "This island is beautiful, but I smell a pungent stench of garbage coming from somewhere."
Sakazuki snorted softly. Hot steam rose in thin wisps from between his fingers. His instincts had already picked up on the commotion in the distance. "There are plenty of filthy pirates roaming around here, capturing slaves. I'll burn them all."
"Go ahead. I've got my own business," Seven said before leaping off the ship and walking in the opposite direction of the city center.
---
Fish-Man District. The Dump. The darkest corner of Fish-Man Island where the laws of the Ryugu Kingdom hold no sway, and suffering breeds pure hatred toward humans.
The moment Seven's boots touched the filthy, cobblestone streets, the air felt different. Hostile stares immediately pierced him from every narrow alley, cracked window, and shabby rooftop.
"Human…" growled a hammerhead fish-man stepping out of the shadows. "A Navy officer dares to enter our territory alone? Are you tired of living, huh?!"
Within seconds, a dozen fish-men armed with various rusty weapons leaped from all directions, surrounding Seven. To them, humans were merely weak creatures whose blood deserved to be spilled.
Spears, swords, and sledgehammers were swung simultaneously at the young admiral's body.
However, there was no sound of flesh tearing. No blood spilled.
Swoosh.
T
he weapons passed right through Seven's body, as if the black-haired man were nothing more than an illusion. The fish-men's eyes widened in shock, losing their balance as their attacks struck only empty air or their own comrades' bodies.
Seven didn't even pause in his stride. His red eyes, bearing the pattern of the Eternal Mangekyou Sharingan, processed every attack without bothering to physically dodge.
He walked through the bewildered crowd, following his hearing toward a massive commotion at the edge of the district.
There, in the middle of an open area surrounded by shipwrecks, a pink-skinned merman youth was being ganged up on by a dozen large mermen.
Though his body was covered in bruises, the youth fought like a lion cornered by a pack of hyenas. His blows were rough, brutal, yet filled with an unbreakable resolve.
"Fisher Tiger," Seven murmured softly. His guess was spot-on. The fish-man looked to be only about fifteen years old—not yet the legend who boarded the Mary Geoise to free the slaves—but the fire in his eyes already burned bright.
Tiger had just knocked his opponent to the ground when a giant octopus-man, who appeared to be the boss of the area, stepped forward wielding an iron mace.
"Arrogant brat, I'll teach you who's in charge here!" roared the octopus boss, swinging his mace toward the exhausted Tiger.
Before the mace could touch Tiger, a straight kick landed squarely on the octopus boss's stomach. The air exploded. The giant octopus-man's body was sent flying backward, smashing a pile of wooden crates to smithereens.
The entire area suddenly fell silent. A gasping Fisher Tiger looked up, his eyes widening as he stared at the back of the man clad in a Navy uniform now standing before him.
Seven slowly turned to survey the area, gazing at the thousands of fish-men now surrounding him with fury.
"Half an hour," Seven said, more to himself than anyone else. He slowly shrugged. "Enough time for a little warm-up."
Thirty minutes later.
No one remained standing in Fishman District except Quentin Seven. Thousands of the district's strongest fighters, including the giant octopus boss, lay on the ground groaning in pain. None were dead, but their bones were shattered enough to understand the vast difference in strength.
Seven sat calmly atop an intact wooden crate. Before him, Fisher Tiger sat cross-legged, his eyes sparkling with admiration. The pink fish-man had just witnessed true martial artistry. Fast, efficient, and flawless.
"So," Seven looked at the octopus boss clutching his bruised chest. "Tell me about this place. You're too weak to be called the rulers of an independent district."
The octopus boss swallowed hard, his pride shattered into pieces under the calm gaze of the human before him.
"B-before… we weren't this weak," the boss said in a hoarse voice. "There were two greatest fighters who once led us. The first boss… he left a very long time ago. His name was Babel, a catfish-man. He lost in the Davy Back Fight and was forced to join a human named Rocks."
Hearing that name, Seven's eyebrows raised slightly. Babel—he didn't know him, but based on Little Kuma's memories, he was one of those who appeared on Rocks' ship. The Rocks era truly gathered monsters from every corner of the world.
"Three years after Boss Babel left," the octopus boss continued, "a new boss emerged. His name was Sunbell. He was incredibly strong. He united the entire district. Under his leadership, not even human pirates dared set foot on this island. Even Prince Neptune respected him."
The boss's eyes dimmed. "But… two years ago, Boss Sunbell decided to set sail for the surface. He joined a group of human pirates… Roger's Pirates."
Seven nodded slowly. Sunbell. That was a very familiar name from the future crew of the Pirate King.
"Since Boss Sunbell's departure, I've taken over this place," the octopus boss said, bowing his head in shame. "But my strength doesn't compare to his. News of his departure spread quickly. Hundreds of pirates began swarming this island like starving ants. They captured mermaids and our kin to sell. Prince Neptune is indeed strong, but he can't be everywhere at once to hold back that wave of greedy humans."
Silence enveloped the district. Fisher Tiger bowed his head, clenching his fists tightly as he felt the helplessness of his race.
Seven stood up slowly. He walked toward Fisher Tiger, bent down, and pointed right in front of the young man's face.
"You," Seven said flatly.
Tiger looked up, his face blank. "M-me?"
"You've got some talent. Your eyes hide a good kind of anger. Join the Navy under my command," Seven offered, his voice brooking no refusal. "I'll teach you how to use that power, so you can protect the Fish-Man Island."
Fisher Tiger's eyes widened. A human? Offering him a place? Without hesitation, Fisher Tiger nodded firmly. "I'm coming with you!"
Seven smiled faintly. He reached into his cloak, pulled out a large roll of cloth, and threw it toward the tallest wall in the district. With a little help from the wind element, the cloth unfurled and pinned itself firmly to the stone wall.
A pure white flag, with a red-and-white Fan emblem in the center.
"From this day forward, this territory is under my protection," Seven's voice echoed throughout the Fish-Man District, heard by every pair of ears still conscious. "If any pirates or human slave traders dare to cause trouble here… mention my name. Let them know that disturbing this place is the same as finding a way to die."
The fish-people lying on the ground stared at the flag with mixed feelings. No human had ever cared about them, let alone a high-ranking military officer.
Seven slipped both hands into his pockets, paying no heed to their reactions. Suddenly, he turned his head slightly toward a dark shadow behind the rubble of a large building about fifty meters from where he stood.
"How long do you plan to hide there, Prince Neptune?" Seven said, his voice flat yet piercing. "What do you think?"