The year was 2042, and the Earth had not known peace for generations. No one remembered the virus that had devastated the world millennia ago. Buried beneath layers of time, it had slumbered—silent and dormant. The ancient plague, however, was not like those that caused death or decay. It was something far worse: it awakened.
The GEN-EV virus, a forgotten relic of Earth's primal past, began its quiet, unstoppable march through the world's remaining living creatures. It didn't ravage the planet with fatal consequences. Instead, it reached deep within, tapping into the ancient beast DNA that lay dormant within every living being.
The result was not death, but transformation. Humanity's genetic code, once stifled and dormant, was now alive with the power of a thousand forgotten beasts. The animal instincts of the past surged within human hosts, giving birth to the new era of mankind: the age of the Mechanics.
In the days that followed, the world was reshaped. Cities rose from the ashes, the old world's knowledge was reclaimed, and new warriors—Mechanics—emerged to wield the most curious weapons known to man: Tools.
Tools were no ordinary weapons. They were mundane objects, everyday items, altered by the infusion of ancient Beast Souls. A simple wrench might become an unstoppable battering ram with the soul of a rhinoceros. A ruler, transformed by the soul of a mantis, could slash through metal like a razor. These Tools did not come to life, but they echoed the primal, relentless power of the beasts whose souls they carried. And as these souls grew stronger, so too did the tools they inhabited.
But not all was calm in this new age. As the world adapted to its beast-infused future, shadows began to rise. Feral Mechanics, those whose Tools had consumed them, turned against humanity, believing they had transcended it. They became the Spliced—half-beast hybrids, wielding corrupted Tools that were wild, unstable, and deadly.
Kazuo Rengai, a 15-year-old boy with no known beast affinity, found himself thrust into this chaotic new world. He entered Yatagarasu Institute, a prestigious academy dedicated to training the next generation of Mechanics. Here, students honed their abilities, synchronized with their Tools, and competed in grueling tournaments to prove their strength.
Kazuo's Tool, however, was unlike any other.
It was a folding utility knife—nothing extraordinary at first glance. But it was infused with the soul of a prehistoric Chimera, a creature of myth whose fragmented essence could not be contained within any single form. His Tool shifted and changed unpredictably, becoming more unstable with each use. Kazuo's Tool was ancient, raw, and dangerous—and Kazuo was unprepared for what lay ahead.
He had no Beast Soul to call his own. His only connection was with his unpredictable Chimera Knife, a Tool whose power defied all reason.
But in this world of chaos and evolution, strength was all that mattered.