A middle-aged woman lay in a hospital bed, her body connected to a network of softly humming machines. Thin cables ran from her arms, chest, and temples, each pulsing with quiet lights that tracked the fragile rhythm of her life. Despite the cold machinery surrounding her, her face was peaceful and calm, as if she were merely asleep.
Her long black hair was neatly arranged across the pillow, untouched by gray. There was not a single wrinkle on her face.
Standing beside the bed was a young man—no more than sixteen years old. He wore a simple high-school uniform, clean but slightly worn. His short black hair was tidy, yet his eyes betrayed the weight he carried. They were filled with deep love and an even deeper sadness, emotions far too heavy for someone his age.
He gently opened the curtain, letting sunlight spill into the room. The sterile white walls softened under its warmth. Dust motes drifted lazily through the air. With practiced care, he replaced the flowers by the bedside, straightened the blanket, and adjusted the pillow, ensuring everything was orderly and clean.
Only when he was satisfied did he sit down.
From his backpack, he pulled out a small book. Its cover was worn from repeated handling, but the title was still visible.
Oz
"We finished Chapter Six yesterday, Mother," he said softly. "Chapter Seven is very interesting. I hope you like it."
He opened the book and began to read aloud, his voice calm and steady.
The young man's name was Nero.
His mother had fallen into what doctors called the Dream of the Underworld, a rare and terrifying affliction. According to medical records, it occurred when a person's consciousness became trapped within the Underworld, a parallel realm that existed beyond physical reality. Their body remained behind, alive but empty, locked in a state of deep coma.
No one knew how it happened.
Worse still, there was no cure.
Some doctors claimed it was kinder to let such patients go—to free resources and spare families the prolonged suffering. Nero refused to listen. His mother had raised him and his older brother on her own. No matter how exhausted she was, Nero could not remember a single day she had not welcomed them home with a smile.
There was no way he would give up on her. Not while even the smallest chance of bringing her back remained.
Of course, Nero was not naïve. He understood that an ordinary person could not accomplish what thousands of doctors had failed to do. But the world was no longer ordinary.
If he could become a Reaper…
Doors would open. Knowledge, medicine, and techniques far beyond conventional science would become accessible—things most people could only dream of.
It would not be easy.
But nothing worth fighting for ever was.
For fifteen minutes, Nero read to his mother, his voice filling the quiet room. The machines continued their steady rhythm, indifferent yet constant. When he finished the chapter, he carefully closed the book.
Suddenly, the hospital door burst open.
A woman in her forties strode inside, her nurse's scrubs rustling sharply. Her expression carried open irritation as she glanced at Nero.
"Hmph. Why are you always here?" she said. "It's not like anything will change. Visiting hours are over. Leave."
Nero looked at her with cold, restrained eyes but did not lose his composure. He was already used to her bitterness. He placed the book back into his backpack, then leaned closer to his mother and smiled gently.
"I'll come tomorrow," he whispered. "We'll continue reading."
He turned and walked toward the exit.
Just as he was about to leave, the nurse spoke again.
"These people are just a waste of resources," she sneered. "What's the point of keeping a bunch of mannequins alive?"
Nero froze.
Slowly, he turned his head. The nurse met his gaze with a nasty smile, clearly provoking him. Anger surged through his chest—but he swallowed it down. The government paid for his mother's care, just as it did for all victims of the Dream of the Underworld. Losing control could put her in danger, and he would never do that.
So he said nothing.
He left the hospital in silence.
Outside, Nero lifted his eyes to the sky. The firmament was painted in shades of pink and red, a familiar sight on Mars, the fourth planet of the solar system. High above the city's center hovered a massive, flaming golden orb.
A Daybreak Heart.
One of many advanced constructs forged after humanity connected with the Underworld, its purpose was to repel hostile entities from that realm. Whenever Nero felt its warmth, a sense of peace and comfort settled in his heart, easing the constant tension within him.
He shook his head. No time to linger. Class was starting soon.
The school was not far from the hospital, and Nero arrived just in time. Although academics were not his true calling, he refused to slack off. He listened attentively, took notes, and did his best to learn as much as he could.
It was only during the final class of the day that his eyes truly lit up.
He was not alone.
The entire classroom buzzed with anticipation.
"Everyone, pay attention," the teacher announced. "Reaper Class will begin shortly. Now, give a proper welcome to Mr. Powell."
The classroom door opened.
A man with gray hair entered. He appeared to be in his fifties, yet his body was strong and well-trained, showing no sign of decay. But the students barely noticed him.
Their eyes were fixed on the spirits hovering at his shoulders.
Two figures floated there, each roughly fifteen centimeters tall. One was human—a warrior clad in samurai armor, posture straight and imposing. The other was entirely different, resembling a strange black bear with a single horn protruding from its forehead, its eyes glowing faintly.
The old man glanced over the classroom, his expression making it clear that enthusiasm was not among his virtues. Fortunately for the students, he did not waste time.
"First," he said flatly, "we'll begin with history."
Several students stiffened. A few rolled their eyes despite themselves. History was something they all knew—something drilled into them since childhood. Still, none dared complain. No one argued with a Reaper.
Mr. Powell's demeanor shifted, his posture straightening as he adopted a solemn expression.
"Everything began on January 31st, 2026," he said. "Doomsday Day. On that date, the Underworld—a parallel dimension to the physical world—made contact with Earth."
The room grew quiet.
"Fiendish spirits we came to call Necros possessed people or used their bodies as gates into our world," Powell continued. "They unleashed a massacre that painted entire continents red with blood."
Even students who usually ignored lectures could not help but sober up. Those events were beyond catastrophe. Humanity had come closer to extinction than ever before.
"But the Underworld was not wholly evil," Powell said. "There were elemental spirits, fairies, and—most importantly—ancient human warriors. Heroes of legend who chose to lend their power to those they deemed worthy."
"In the beginning, different cultures," he explained, "gave these warriors different names. Some called them Gods of Death. Others, Shinigami. The titles varied, but the role remained the same.
"Today," Powell said, "we call them Reapers, warriors capable of harnessing the strength of the Underworld. And those by their side are called Guardian Spirits."
At that moment, the samurai spirit hovering near Powell's right shoulder shifted into a more imposing stance. Its presence alone drew awe and reverence from the students, its silent authority pressing down on the room.
"Through bloodshed and determination," Powell continued, "humanity pushed the Necros back. With our new abilities, we reinvented our techniques and expanded beyond Earth. We terraformed new planets."
His gaze flicked briefly toward the window.
"Mars was settled forty-six years ago."
A faint smile tugged at Nero's lips. Humanity had many flaws—anyone mature enough could admit that. But when faced with horrors beyond measure, humanity did not break. It adapted. It evolved. It rose higher than before.
Nero forced himself to stay focused as Powell continued.
"Now, regarding ascension from an ordinary human to a Reaper," the old man said. "The first step is forming a bond with a spirit through a Soul Vow."
A faint murmur rippled through the class.
"The Guardian Spirit connects with your soul," Powell explained, "and by combining your Mana with their Underworld Energy, a Reaper Core is formed. That core is where the spirit resides. It anchors them to the physical world—and it is the foundation of a Reaper's power."
Powell paused, giving the students time to absorb the information.
"Understand this," he said. "The core is both your strength and your limit."
Though the lecture itself might have seemed dull, Powell showed no signs of slacking. His voice remained steady and precise.
"Now, the deciding factor in whether you become a Reaper is not the Guardian Spirit," he continued. "It is your Mana."
Several students straightened unconsciously.
"Mana has many interpretations," Powell said, "but in essence, it is the manifestation of your will and life force. It is the energy that allows you to perceive the Underworld—and, with the aid of your Guardian Spirit, to wield its power in combat."
He folded his arms.
"Mana is determined at birth. While it can grow through training, its foundation does not change. If it starts low, it is difficult to raise significantly. If it starts high, growth comes more easily."
As he reached that point, Powell's sharp gaze swept across the room. Several students wore conflicted expressions. At their age, their Mana levels had already been measured. They knew, at least roughly, where they stood.
Powell did not soften his tone.
"It is better to be clear now than to waste years chasing an impossible dream," he said bluntly. "While spirits—especially ancient human ones—do not require strict binding vows, they do care deeply about Mana."
The samurai spirit's eyes glinted faintly.
"Mana determines whether a Guardian Spirit can evolve into higher forms," Powell continued. "If your Mana is too low, no spirit will bind with you. It is that simple."
Nero took a slow, steady breath.
He could not hide the bitterness that flickered across his expression. He was exactly the type Powell described—born with a low innate Mana level. The kind most spirits would never consider.
However, his heart did not break, and he clenched his fist beneath the desk.
Life had not given him talent. It had not given him an easy path. But it had given him resolve—and a reason to keep moving forward.
He had a plan.
It would be difficult. It would demand effort far beyond what others faced.
But it would allow him to become a Reaper.
And Nero had never been one to back away from a fight worth winning.