It was an unremarkable morning in Sendai—or at least, by human standards, it was supposed to be. The sun rose lazily over the city, glinting off the tiled rooftops and bustling streets, while the faint scent of sea salt and cherry blossoms lingered in the air. But in the undercurrent of normality, the world still bore the scars of its ancient history, a past where monsters had rained down upon humanity without warning, a thousand years ago during the Haen Era. That age had been the pinnacle of human civilization yet simultaneously its most fragile moment. It was an era when humanity first confronted the truth: that life as they knew it was not sovereign, and that the world was governed by monstrous forces far beyond comprehension.
In those days, monsters appeared as if summoned by the earth itself—ghouls, beasts, demons, dragons, and special-rank anomalies, each classification reflecting the level of threat they posed. Ghouls were small, vicious creatures, capable of killing ordinary humans with little effort. Beasts were larger, capable of destabilizing entire towns if left unchecked. Demons dwarfed even the strongest human armies, destroying entire prefectures in their wake. Dragons, the living nightmares of legend, were titanic entities whose presence alone could reshape countries over decades. And finally, there were the special-rank anomalies: unpredictable, intelligent beings with strength and cunning that could rival the most disciplined humans, and sometimes, even other monsters.
For survival, humans had learned to harness senjutsu, the latent energy within every living being. Senjutsu could be manipulated and weaponized, allowing trained individuals to fight monsters on relatively equal footing. Some elite slayers went further, using the cores of monsters themselves as weapons—living, pulsing conduits of power that could be shaped into blades, armor, or devastating attacks. These techniques, however, required discipline, precision, and inborn resonance. Misuse often led to death or total corruption of the body.
My name is Jin Takasaki, and today marked my first day at the Slayers Association of Sendai. The association, founded sixty years ago, was designed to organize those capable of manipulating senjutsu into a structured military force. Its hierarchy consisted of captains, lieutenants, battalion leaders, squadron leaders, officers, and soldiers, each with responsibilities corresponding to their skill and resonance levels. The primary purpose of the association was simple yet daunting: train humanity's best to protect cities from monsters before they could wreak havoc. But for me, it was more personal. It was where I would step out of childhood and face a reality that few could even comprehend.
A thousand years ago, the world had trembled beneath the shadow of Laplace, the so-called "Monster King." He had ruled Japan with unmatched ferocity for a decade, his white hair and flawless body a symbol of his inhuman perfection. Regeneration matched only by the mightiest monsters, strength that defied the limits of human physiology, and intelligence that seemed to anticipate every attack, Laplace had been the apex predator of the age. When twenty nations united their strongest warriors in a desperate campaign to stop him, few survived. In the end, Laplace was sealed, not killed, into twenty fragments, leaving behind whispers of a man whose mere presence had been enough to bend history. How a single human had risen to such heights remained a mystery—a question that fueled many of the association's legends.
My First Day
The training grounds of the association were vast, a sprawling complex that could rival the size of small towns. They had specialized arenas, simulators for monster combat, and chambers designed to safely channel the cores of captured creatures. As I stepped into the main hall, I caught sight of Hana Fuji, my childhood friend and now captain of the 7th Division. Her presence was commanding yet familiar, a comforting anchor amid the chaos of my nervous thoughts. Hana had joined the association years before me, her raw potential recognized early on, propelling her swiftly through the ranks.
Beside her stood Reo Arakawa, her lieutenant. He was a man in his early forties, tall, with a chiseled face etched by decades of battle experience. His combat suit glinted under the morning sun, the standard gear of high-ranking members designed to channel the cores of monsters into usable energy. The suits were marvels of technology and sorcery combined, a testament to the association's ingenuity. Today, one of these suits would be mine.
I followed them into the training room, heart pounding like a war drum. The room was stark, walls lined with pulsating crystals—containers for monster cores—casting a faint red glow across the metallic floor. Reo handed me my own combat suit, its weight surprisingly light, almost like it was waiting for me to become one with it. They began measuring my resonance, the natural affinity my body had for senjutsu. Most recruits averaged between one and five percent—the upper limit their bodies could handle without injury. Years of training with Hana had forged something exceptional within me. When I released my energy, the gauge spiked to eight percent, far beyond the normal range. The trainers' eyes widened. In an instant, my rank was confirmed: I was an officer.
First Mission
Weeks passed in a blur of drills, simulations, and rigorous tests. Then came my first mission: a beast-class monster had been spotted tearing through Sendai, leveling several buildings. Alongside other officers, I was dispatched to engage it.
The battlefield was chaotic. Smoke choked the streets, shattered buildings lay in piles of rubble, and the cries of civilians echoed faintly in the distance. I approached the beast, a hulking creature covered in jagged scales, teeth long enough to pierce steel. My sword, a weapon forged from a core of a captured demon, shimmered with contained energy. I raised it, intending to cleave through its neck. And then it happened.
The blade snapped. In an instant, I was bisected, pain erupting in every fiber of my being. Darkness claimed me.
The Temple
When I opened my eyes, I was in a place unlike any I had seen—a temple floating in a crimson sea of spider lilies. The scent of blood and decay mixed with a strange serenity, as if life and death were intertwined here. From the center emerged a figure with white hair, impossibly radiant and terrifying at once.
He approached and, without hesitation, stabbed his hand straight through my head. Blood flowed like ink across my vision, but instead of dying, I felt life surge through me. "Live," he commanded.
The transformation was immediate. My body healed, a horn sprouting from my forehead, and I felt the surge of unimaginable strength. With a thoughtless, primal force, I tore through the beast that had once bested me. Yet, even as I fought, I felt a presence—not entirely mine—struggling to dominate. This was not me. It was Laplace, or some fragment of him, within me.
My rampage continued, my horn growing larger, my power swelling beyond reason. The world became a blur of destruction. Only Reo's voice, piercing through the storm of my fury, finally knocked me unconscious, dragging me back to reality before I could lose myself completely.