Prologue

Kazuto wandered the dim streets of City K, burdened by a purposeless existence. Abandoned by society, with no job or aspirations, he merely existed. That night, however, fate threw him a lifeline in the form of a young boy clutching an envelope as if it were his life.

"Kid, what's with the letter?" Kazuto asked, his voice monotone but curious.

The boy, barely fifteen, looked up with eyes full of determination. "It's for my father. It's the only thing I have left of him. I need to deliver it."

Before Kazuto could respond, a chilling laugh echoed. Emerging from the shadows came a grotesque Kaijin—a towering, slimy, toad-like creature. Its bulbous eyes locked onto Riku.

"You!" it bellowed. "You're the brat who spilled water on me last week! Do you know how long it takes to clean this glorious body? You'll pay for that insult!"

Riku froze as the Kaijin's long tongue lashed out, narrowly missing him.

Kazuto stepped forward, placing himself between Riku and the beast. "Seriously? Over spilled water? Get over yourself."

The Kaijin sneered. "Out of my way, human, or you'll meet the same fate!"

Kazuto chuckled, a hollow sound that masked the emptiness inside him. "I've been wandering through life without a purpose. But seeing this kid fight to protect something so simple... it woke something in me. I've decided. I'll be a hero."

The Kaijin roared and struck Kazuto with its tongue, sending him crashing through a wall. Dust and rubble filled the air, and Riku screamed, paralyzed with fear.

"Kazuto!"

The Kaijin turned back to Riku. "Now, brat, it's your turn."

Kazuto's voice cut through the chaos. "Hey, slimy."

The Kaijin turned to see Kazuto emerging from the rubble, bloodied but calm. "You talk too much."

Kazuto launched himself at the creature, dodging its attacks effortlessly. He noticed a glowing sac on its throat—its weak point.

With a single, devastating punch, Kazuto struck the sac. The Kaijin exploded into a shower of slime, collapsing lifelessly.

Kazuto retrieved the envelope and handed it to Riku. "Here. Your letter."

Riku's hands trembled as he took it. "Thank you. I'll never forget this... or you, Kazuto."

As Riku disappeared into the night, Kazuto stood alone, staring at the remnants of the battle.

"For once... I felt alive," he muttered. "Maybe I can do this."

Determined to become the strongest, Kazuto committed to an unrelenting training regimen:

1. The Infernal Run (50 km/day)

Kazuto ran 50 kilometers daily across treacherous terrain—jagged rocks, slippery ground, and steep inclines—breathing only through his nose and exhaling through his mouth. His legs screamed in agony, but he pushed forward, tearing and rebuilding his muscles daily.

2. Burpees of Despair (1,500 reps/day)

Each burpee ended with a three-meter jump, followed by a five-minute plank every 100 burpees. If he failed, he started over. His body ached, but his resolve hardened.

3. Relentless Push-Ups (10,000 reps/day)

Kazuto alternated between one-handed, explosive, and diamond push-ups. Resting was not an option; every failure meant a thirty-second break before continuing. His arms became unyielding pillars of strength.

4. Total Squats (10,000 reps/day)

Every 500 squats were followed by 100 two-meter vertical jumps. His legs, once ordinary, transformed into unstoppable engines of power.

5. Inhuman Pull-Ups (1,000 reps/day)

Kazuto alternated between explosive pull-ups, L-sit pull-ups, and variations in grip. His back and arms grew absurdly strong, capable of withstanding incredible strain.

6. Final Sprints (100 x 100 meters)

Kazuto sprinted at full speed, resting only ten seconds between each set. If his speed faltered, he repeated the last ten sprints. His explosiveness became unparalleled.

Daily Schedule

Kazuto trained ten hours a day, seven days a week, sleeping only four hours a night. His diet was spartan—natural foods like fruits, vegetables, and lean protein. Each day was a mental and physical war, but Kazuto's iron will refused to let him stop.

One Year Later

Kazuto's strength was extraordinary. A single punch could send Kaijins of Tiger-level threats flying through buildings. His power grew exponentially, yet he pushed himself harder, unwilling to stop.

Two Years Later

No rival could stand against him. Every Kaijin fell with one blow. The thrill of battle began to fade, replaced by an emptiness he couldn't shake.

Three Years Later

Kazuto was unmatched. His strength, now limitless, became a burden. The excitement of battle was gone. Every punch ended a fight before it began. Alone in his small apartment, he stared at the news, where Kaijins of Dragon-level threats wreaked havoc.

"They'll lose," he muttered. "Again."

Kazuto sighed, closing his eyes. "I'm too strong... What's the point?"

In a world overrun by monsters, Kazuto's strength was both a gift and a curse. His overwhelming power left him searching for something more—a purpose, a challenge, a reason to fight.