I Failed to Be a Hero, So I Became the God of Three Realms

Kaito Aragami sat slouched in his seat, the hum of the professor's voice drifting through the classroom. He was doing his best to pay attention, but the boring lecture on quantum mechanics wasn't exactly riveting. It wasn't that he didn't care—it was just that he had long since outgrown the excitement that high school once promised. Now, everything felt... routine.

Another lecture. Another day. Another hour wasted.

His eyes began to wander, staring blankly at the clock as the seconds ticked away. His fingers drummed rhythmically on the desk, trying to stave off the overwhelming sense of déjà vu. The world around him felt like a fog. Distant. Unimportant.

Then, without warning, the classroom vanished.

Kaito's breath caught in his chest. The warm classroom air was replaced by an icy coldness, the weight of the world around him growing heavier with each passing second. His body jerked, his head spun, and before he could make sense of what was happening, everything shifted.

A flash of light. A burst of intense magic.

He could feel the presence of something enormous—the magic, raw and untamed, vibrating through every inch of his body. He tried to scream, but the words wouldn't form. The world was spinning, twisting, until the ground beneath him felt… different. Solid.

Kaito gasped and stumbled, catching himself on his knees.

As the light receded, he blinked, his eyes adjusting to the new surroundings. He was no longer sitting at his desk, surrounded by classmates. Instead, he found himself in an enormous chamber. Tall, grandiose walls of stone stretched upward, lined with towering columns, and the air felt thick with power—raw, unrefined magic. The chamber was dimly lit by eerie torches that flickered with unnatural flames. His senses were overwhelmed by the magnitude of it all.

And he was not alone.

Around him stood a group of mages, dressed in dark robes, their eyes wide with awe and fear. The air around them crackled with magic, and their faces were filled with a mix of excitement and disbelief.

At the center of the room stood a man—a King, by his regal attire—his posture straight and commanding. His eyes locked onto Kaito, sharp and unwavering. He wasn't just looking at Kaito; he was studying him. As if Kaito were a puzzle he had been waiting to solve.

"What... is this?" Kaito breathed, standing up, trying to make sense of his new reality.

"Ah," the King's voice rumbled, deep and imposing. "So you've arrived. The hero who was summoned to save our world." His words were spoken with authority, but there was an undercurrent of unease, as if the King himself wasn't entirely sure what would happen next.

Kaito tried to take a step forward, but his legs felt heavy, as if the ground itself was resisting his movement. The room spun around him, the gravity of the situation setting in. Summoned? What the hell was going on?

"You must be confused," one of the mages spoke up, their voice shaky but filled with reverence. "This is the summoning chamber. We brought you here—no, we summoned you from your world to save us."

Kaito opened his mouth to respond, but nothing came out. His thoughts were jumbled, his mind struggling to keep up with the surreal situation. Summoned? He wasn't some kind of fantasy hero. He was just a regular guy, going through his mundane high school life. He didn't ask for this.

"Look around," the King said, his voice steady but tinged with desperation. "Our world is dying. A great darkness threatens to consume everything we know. We need you, Hero. Only you can stop it."

Kaito's heart raced. He wasn't in his classroom anymore. This wasn't Japan. This wasn't reality. And there was no way he was going to be some hero.

"I... I don't know what you're talking about," Kaito stammered, shaking his head in disbelief. "I'm no hero."

The mages murmured among themselves, casting nervous glances at each other, unsure of how to proceed. The King stepped forward, his eyes never leaving Kaito.

"You have no choice but to accept your fate," the King declared. "This world has already chosen you. We summoned you, and now you must fulfill your role."

Kaito stumbled back, his hands raised in disbelief. "I didn't ask for this! I don't belong here!"

The air around him thickened, the pressure in the room mounting. There was no escape from the situation. No way to go back.

The King's expression softened, but his words were firm. "The world has already decided. You are the one we need, whether you accept it or not."

Kaito looked around at the mages, all of whom were staring at him with anticipation. The pressure was suffocating. He could feel their gaze—expectant, hopeful, as though his mere presence held the key to their salvation.

What the hell am I supposed to do now?

Before he could gather his thoughts, a voice resonated deep within him, echoing from the very core of his being.

"You are not powerless, Kaito Aragami. You are more than you know."

His heart skipped a beat. The voice felt like it was his, but also not. It wasn't the King or the mages. It was something else—something vast, something... ancient.

Kaito's knees buckled, and he collapsed back against the stone floor. He felt dizzy, his vision swimming. Whatever was happening, it was far beyond anything he had ever imagined.

The mages murmured in unison, sensing the magic swirling around him, growing stronger by the second.

"You must learn to control it," the King said, his voice cutting through the tension. "For now, this world depends on you."

Kaito looked up, sweat dripping down his face. He didn't know where to go from here. This wasn't his world. This wasn't his fight.

But there was no turning back. Not anymore.

Kaito barely had time to process the weight of the King's words before he was grabbed by the arms and roughly pulled to his feet by two of the mages. His head spun as they ushered him toward another chamber—a stark, sterile room filled with strange, pulsating energy.

"This is the Evaluation Chamber," the King explained, his voice colder now, more businesslike. "We must determine your magical affinity and capacity. It will tell us what powers you possess, so we can train you accordingly."

The mages shoved him forward, and Kaito stumbled, barely catching himself. The King's gaze followed him, as if waiting for something monumental to happen.

At the center of the room stood a pedestal, and atop it sat a glowing orb. It shimmered with an ethereal light, casting strange reflections on the stone walls. One of the mages gestured toward it.

"All you must do is touch it," the mage instructed. "It will reveal your magical affinity, your potential."

Kaito wasn't sure what to expect, but he didn't want to be rude or make the situation worse. He hesitated for only a moment before walking up to the pedestal. The orb hummed as his fingers brushed against its surface.

The orb flared to life.

It blazed with a brilliant light, more intense than any Kaito could have imagined. The chamber was suddenly filled with an energy that made his skin tingle, an overwhelming surge that almost knocked him off his feet.

Then, the light began to fade.

The mages were silent as they observed the orb, but Kaito's confusion grew. His fingers still rested on the orb, but nothing had changed. The chamber was quiet now, except for the soft echo of the orb's fading hum.

The King stepped forward, his face unreadable. "What...?" he murmured. He turned toward the mages, his tone shifting from calm authority to something darker. "Why is there no reading?"

The orb's glow had faded completely. The surface now appeared cold, lifeless.

The mage nearest to Kaito stammered, "W-We've never seen anything like this, Your Majesty. No magical affinity... at all?"

The King's frown deepened as he crossed his arms. "Impossible. No one has ever had no magical affinity. It's... unheard of."

Kaito's stomach sank. No magical affinity? Was he just... useless?

But then, something else caught the eye of one of the mages—something that shouldn't have been there at all.

The orb's surface shimmered once more, briefly, before an unfamiliar symbol appeared.

It wasn't glowing with the usual colors that would represent a magical affinity. Instead, the orb displayed a strange symbol—something resembling a zero.

The room fell into an uncomfortable silence.

The King stepped forward, leaning in to study the symbol. "What... is this?" he muttered, his voice low. His eyes darted to the mages, their faces twisted in confusion.

The mage nearest Kaito leaned closer to the orb, his expression twisted with unease. "It's... it's zero, Your Majesty," the mage said, but there was doubt in his voice. "There's no color, no affinity. And this symbol... it looks like zero, doesn't it?"

The King's face was filled with disbelief. "Impossible. No affinity, and no capacity..." His voice trailed off as the implications hit him.

They didn't know what the symbol meant. None of them had ever seen anything like it. To them, it was just a symbol that resembled zero—a sign of nothingness.

Kaito's heart pounded. Zero... The word echoed in his mind, though he knew it wasn't right. He felt like something was wrong, that the world didn't understand him. But at that moment, there was nothing he could say or do.

The King's tone grew colder, more dismissive. "If you have no affinity... and no capacity... then you are useless to us."

The mages nodded, as if confirming the King's judgment.

Without another word, they grabbed Kaito and began to drag him from the chamber.

"You'll be banished to the outskirts," the King declared, as though Kaito were nothing more than a mere inconvenience. "Maybe there, you'll learn to survive in the wilderness. If you even have the will to do so."

The words felt like a slap, but Kaito said nothing. He had no choice but to follow them.

They dragged him through the castle, through stone corridors and towering gates, until they reached the edge of the kingdom—the desolate, barren outskirts where even the Kingdom's own soldiers dared not venture.

The last thing Kaito saw before he was shoved into the wilderness was the cold, pitiless eyes of the King.

Alone, abandoned, Kaito stood at the edge of the kingdom, the wind whipping through his hair. His heart sank into the depths of despair.

But before he could fully process what had just happened, the ground beneath him began to tremble.

A massive shadow swept across the land, casting a chill over him. He turned slowly, his eyes wide as the figure of a demon emerged from the darkness.

A Demon General.

It was then that something shifted within Kaito, something deep and ancient. Then, it happened.

Three Hundred Years Later...

The world had changed dramatically over the course of three hundred years. The once-mighty King had passed on long ago, leaving behind only a legacy of peace and order. Now, the kingdom was ruled by an orderly structure, where the worship of the God—known only as the Creator—was central to life. This peaceful world had been guided by the divine for generations, and it was in this time that the five new arrivals found themselves summoned.

The new heroes were ushered into a grand, marble-walled hall, standing side by side as they tried to make sense of their situation. Among them were Tatsuya Tanaka, a tall, determined-looking young man; Hanae Fujimoto, a serene, soft-spoken girl; Usagi Inuzuka, a rabbit-eared girl whose gentle eyes hid a fiery determination; Riko Yamamoto, an athletic and confident young woman; and Reiji Sato, a calm and reserved boy who seemed to radiate quiet potential.

Standing before them was the King, a man whose age seemed to have diminished with time. Though old, his presence was powerful, exuding authority that could never be questioned. "Welcome," he said, his voice rich and commanding, though tinged with weariness. "You have been summoned here for a reason. The God has chosen you to play an important role in the world you now find yourselves in."

The five glanced at each other, confused. They had only just arrived, still grappling with the notion of being summoned to a foreign world. What could their purpose be?

"The reason you are here is simple," the King continued, his gaze sweeping over them. "A darkness grows, and the balance of the world is threatened. The Demon Empress, Nyx Umbrosia, now leads the Umbrosian Empire, and her influence continues to spread across the land. Few know of the true extent of her power, but it is said that her magic is more potent than any before her. Her plans are unclear, but one thing is certain—she will stop at nothing to claim all of Aurestia for herself."

A murmur of unease passed through the group. None of them had heard of Nyx, but her name felt like a whisper of danger.

"She is the daughter of the former Demon Empress, Lilith Umbrosia," the King continued. "However, the people know her only as the new ruler of the Umbrosian Empire. Her rise to power has been swift and unsettling. While she operates in the shadows, her ambition is clear, and it will be your task to face the challenges that come with it."

The King's words hung in the air, heavy with the weight of responsibility. For a moment, the group remained silent, contemplating the gravity of the situation.