Konoha, Training Ground 4.
What used to be a relatively open stretch of woodland edge was now a complete wreck.
Trees as thick as bowls lay toppled in every direction, their fresh splintered ends gleaming white. The once-solid ground was riddled with craters and crisscrossing trenches, as if a giant beast had stomped through it over and over.
BOOM! BANG! THUD!
Heavy, drum-like impacts mixed with the sound of cracking rock rang out nonstop. Each strike made the earth tremble faintly and sent dirt and stones flying.
Two figures blurred across the limited space at speeds the naked eye could barely follow—colliding, separating, then slamming together again even harder.
One silhouette was agile and lightning-fast, yet every direct clash forced it backward under overwhelming power.
The other was built like a living mountain. Every movement carried crushing weight, as if the body wasn't flesh and blood at all, but forged from solid steel.
Another raw, no-frills punch!
THUD!
The shockwave exploded outward. The smaller figure—Shinichi Higashino—shot backward like a cannonball. He slammed into a massive tree that would take two men to hug, the trunk groaning in protest before snapping cleanly in half.
Wood chips flew everywhere. Shinichi let out a muffled grunt, using the collapsing tree as a cushion to flip and land. His feet plowed two long furrows into the dirt before he finally skidded to a stop. His chest heaved, blood and Cakra roiling inside him, while both arms burned with numbness.
His training clothes were soaked through with sweat and dirt, clinging to every swollen muscle. Rips and tears exposed skin covered in fresh bruises and flushed red.
Yet his eyes burned brighter than ever. They stayed locked on the massive silhouette gradually emerging from the swirling dust cloud ahead. His breathing was heavy, but filled with a near-maniacal focus.
The dust thinned.
A towering figure easily two and a half meters tall stood revealed.
It wore Konoha's forehead protector squarely on its brow, but it was no human.
Thick, steel-hard silver-white fur covered its entire body, gleaming with a cold metallic sheen under the sunlight filtering through the trees.
Every muscle bulged like carved granite, raw and explosive, radiating a primal power that made the heart skip.
Its round golden eyes were pure wildness—sharp, fierce, and ancient. Slightly parted lips revealed gleaming fangs.
Just standing there, it gave off the oppressive aura of a beast from the age of legends.
This was the Third Hokage Sarutobi Hiruzen's personal summoning beast, the legendary Ape Demon King, famed across the shinobi world for its unmatched strength and diamond-hard body.
When Shinichi had told the Third Hokage he wanted to train under a senior with an abnormally powerful and nearly indestructible physique, the old man had immediately thought of his longtime partner.
The Ape Demon clan was born with tyrannical physical power. Their bones and muscles far surpassed human limits. They didn't even need chakra to shatter boulders or split the earth with a casual swing.
Their muscle density and bone strength were simply insane—blunt-force impacts were naturally dispersed, ordinary blades barely scratched them. They were walking fortresses of living steel.
And so, the Ape Demon King had become Shinichi's personal trainer for this special session.
At their first meeting, the Ape Demon King had been blunt: the Ape Demon clan had no fancy, mysterious training methods. Their way of tempering the body was simple and brutal.
Fight. Take hits. Feel the impact. Endure the pain. Push past every limit until every muscle fiber and bone was reforged in the furnace of combat.
After each brutal session came their clan's secret medicinal baths and ointments—accelerating recovery, repairing hidden damage, and locking in the gains so the body could grow stronger through repeated destruction and rebirth.
In short: get beaten half to death, then heal.
The short lull in the center of the field gave Shinichi a moment to steady his breathing. He felt the burning ache in his arms and the white-hot fire running through his muscles.
The Ape Demon King followed the simplest creed of his kind: only when pushed to the absolute brink—or beyond—could flesh and blood truly evolve.
His training style was merciless: as long as it didn't kill you, it wasn't hard enough.
This kind of sparring had been going on for days. Every evening Shinichi ended training covered head to toe in bruises, skin barely intact anywhere, bones feeling like they were about to fall apart.
Luckily, the Ape Demon King's secret medicines were miraculous. Combined with Shinichi's already superhuman constitution and the [Glutton King] trait that let him absorb nutrients and convert energy at terrifying efficiency, he was able to endure the insane daily grind.
"Kid! Pay attention!"
The Ape Demon King's voice boomed like a bronze bell, carrying a metallic edge. The moment the words left his mouth, his massive body dropped into a low crouch, legs tensing with power that made the ground crack.
BOOM!
The earth beneath his feet collapsed into a crater as the Ape Demon King launched himself skyward. His enormous frame moved with shocking speed and explosive force that completely defied his size.
Like a meteor falling from the heavens, he fused his terrifying weight with the momentum of descent into the most primal, violent attack imaginable—smashing straight down toward Shinichi!
Shadow swallowed everything. The wind howled. The very air screamed as it was violently displaced!
Can't take this head-on!
The instant the Ape Demon King jumped, Shinichi reacted. He didn't retreat or dodge sideways—the attack's range was too wide.
Instead, he charged forward, straight into the dead zone beneath the ape, dropping his body so low he was almost skimming the ground like a black lightning bolt.
WHOOSH!
At the last possible moment, Shinichi slipped through the edge of the landing zone by a hair's breadth. The savage wind pressure nearly yanked him off his feet and scraped his exposed skin raw.
BOOOOOOM!!!
The Ape Demon King crashed down like a falling star. The impact point became the center of a violent shockwave that rippled outward in a perfect ring. The hard ground buckled like water, then exploded.
Countless stones and chunks of earth were hurled into the air, carving out a terrifying crater over ten meters wide.
Shinichi didn't pause for even a heartbeat. The moment he escaped the killing blow, his counterattack ignited. Using the flying sand and debris as cover, he spun violently, twisting his waist and pouring every ounce of strength and chakra into his right leg. A vicious side kick—sharp as a battle-axe—whipped toward the Ape Demon King's ankle joint right after landing, the spot least able to generate power!
BANG!
Leg bone met ankle. The sound was like kicking a solid steel pillar.
The Ape Demon King's body only swayed slightly. He didn't move half a step.
"Not bad power, but still lacking!" the Ape Demon King rumbled. His massive arm swept out casually, like a falling tree trunk, carrying unstoppable force.
Shinichi yanked his leg back and crossed both arms in front of his chest.
THUD!
Arms collided with the ape's forearm. Shinichi felt like he'd been hit head-on by a charging tank at full speed. Both blocking arms went instantly numb. His entire body was sent sliding backward uncontrollably, feet carving deep trenches in the ground as he flew more than ten meters before finally bleeding off most of the impact.