When Sengoku woke the next morning, the throbbing in his left ankle was sharper than he had anticipated.
As he tried to step out of bed, a distinct, tearing sensation shot up his calf, forcing his movements to a sluggish halt. The sprain from his botched jutsu experiment, compounded by the explosive movements during the alleyway ambush, was not something that could be slept off in a single night. Even with his enhanced vitality, tissue damage of this extent required time.
After carefully examining the swelling, Sengoku calmly accepted the reality of his situation. He felt no frustration or anxiety. Today, physical training was off the table; pushing through would only compound the injury and delay his long-term progress.
He washed up, ate a simple meal, and stayed in his room.
Moving to a spot where the morning light filtered through the window, he brought out a cracked, wooden puppet joint he had scavenged, along with his two scrolls on puppetry and chakra control. Sitting comfortably, he condensed a faint aura of chakra at his fingertips and began his daily precision thread exercises.
Between exercises, he studied the scrolls. He cross-referenced the detailed anatomical diagrams of the human meridian system, specifically the complex clusters around the feet and lower legs. Lightly pressing his fingertips against his swollen ankle, he memorized the exact spatial coordinates of each pressure point, running endless mental simulations on how different micro-pulse combinations would dictate his body's kinetic trajectory.
He spent the entire day immersed in this quiet, analytical study.
As January slipped into February, his ankle finally healed.
Sengoku returned to his secluded corner of the training grounds, resuming his grueling, monotonous drills. However, his movements were fundamentally different from a month ago.
Gone were the crude, crater-forming dashes and clumsy pivots. His footwork had taken on an unnerving, almost ghostly quality. When he moved, he would dart forward like a striking viper, only to instantly halt or violently shift directions at physically impossible angles. The tracks he left in the sand were no longer messy divots, but dense, overlapping, geometric scuffs that resembled the scales of a slithering snake.
The Puppet Shunshin was nearing a state of practical application.
Its speed, flexibility, and precision vastly outclassed the academy's standard Shunshin. Yet, it was far from perfect. Chaining multiple high-speed directional shifts placed an immense tax on his chakra reserves and required a terrifying level of mental processing. He couldn't sustain the technique for long, and the sheer torque generated by the extreme pivots still placed a dangerous load on his knees and ankles.
Standing in the center of the sand, he meticulously analyzed the kinetic feedback of his latest successful dash, searching for microscopic inefficiencies to prune.
His daily spars with Araki Ryo had lost all meaning. Fighting Araki felt like an adult humoring a toddler; it required zero mental bandwidth, failed to push his physical limits, and provided no valuable data for his jutsu development.
Sengoku scanned the empty training ground. 'Where can I find a stronger opponent?' he wondered. Without a proper whetstone—a live combat environment that genuinely threatened him—the Puppet Shunshin would forever remain a theoretical prototype.
Just as he was contemplating his next move, four figures blocked the exit to his training area.
Leading the pack was a heavily built teenager, likely twelve or thirteen years old, radiating aggressive, untempered anger. It was Jiro, Saburo's older brother, a student on the verge of graduation. Crouched nervously behind him was Saburo, flanked by his two familiar lackeys.
"Finally caught you, you little rat!" Jiro bellowed, jabbing a thick finger at Sengoku. "You've been dodging me for a month. Let's see you run today!"
Sengoku's expression remained perfectly flat. He ignored the older boy entirely and locked eyes with Saburo. "Saburo. You should remember exactly what I told you last time."
Saburo flinched under the dead-eyed stare, but emboldened by his brother's massive frame, he shrieked back, "Do you see this, Jiro?! See how arrogant he is?! He actually threatened to break our legs!"
"You little bastard!" Jiro roared. Simple-minded and thoroughly manipulated by his younger brother's exaggerated sob stories, his temper boiled over.
Abandoning any pretense of restraint, Jiro kicked off the ground. He charged like a raging bull, throwing a massive, wind-whipping punch directly at Sengoku's face. He knew enough to keep it a fistfight and refrain from using lethal ninjutsu, but the kinetic force behind an older academy student's punch was worlds apart from Saburo's weak flailing.
Watching the heavy fist close in, Sengoku didn't feel a shred of fear. Instead, a cold light sparked in his eyes. 'A whetstone just delivered itself.'
A fraction of a second before the punch connected, Sengoku moved.
He didn't step back. He triggered a complex sequence of micro-pulses beneath his soles. His body slid diagonally backward in a smooth, rigid glide, his posture remaining perfectly upright. It didn't look like a human dodging; it looked like a wooden puppet being yanked to safety by invisible strings.
"Huh?" Jiro grunted, his momentum pulling him forward as his fist hit empty air.
Sengoku didn't give him a moment to process the anomaly. Shifting the chakra output to his right foot, Sengoku launched himself forward like a ghost, reappearing at Jiro's blind flank. He swung a vicious knife-hand chop toward the older boy's exposed ribs.
Relying on his superior physical reflexes, Jiro hastily yanked his arm down to block.
But mid-swing, Sengoku aborted the chop. He seamlessly shifted his weight, rotating his wrist to drive a heavy, blunt punch directly into the nerve cluster of Jiro's blocking arm.
Jiro's arm went instantly numb. Panicking, the older boy triggered a standard Shunshin to blast backward, swinging his other fist in a wide, desperate arc to create space.
Sengoku stayed on him. Ducking under the wild swing, he pivoted on a dime and pressed the assault. His movements were a flawless, flowing sequence of unnatural angles and sudden accelerations. He sidestepped Jiro's brutish strikes with millimetric precision, finding the most agonizing, unorthodox angles to deliver his counterattacks.
For several minutes, the training ground echoed with Jiro's furious, frustrated roars. He was swinging at shadows, unable to land a single solid hit, while Sengoku dismantled him piece by piece.
Sengoku lacked the raw physical power to knock the older boy out in one strike, but his timing was absolute. Every time Jiro overextended, every time he drew a breath, Sengoku's fists and elbows found a weak point.
Despite his superior stamina and chakra reserves, Jiro was suffocating under the pressure. The fight was ending.
Spotting a microscopic lag in Jiro's footwork, Sengoku feinted a high punch. As Jiro raised his guard, Sengoku fired two rapid, consecutive pulses, blurring completely out of the teenager's field of vision. He materialized directly behind Jiro, channeled every ounce of his physical strength into his right leg, and delivered a devastating front kick squarely between Jiro's shoulder blades.
Thud.
Jiro stumbled forward, his legs finally giving out. He crashed hard into the dirt, gasping for air, entirely unable to push himself back up. He stared at the sand in absolute shock. He had just been systematically dismantled by a second-year student.
Standing a few feet away, Sengoku was sweating heavily, his chest heaving. The consecutive use of the Puppet Shunshin had drained his chakra reserves to the dregs and pushed his muscles to their absolute limit. But as he looked at the downed teenager, a cold sense of satisfaction washed over him.
The jutsu's combat viability was confirmed.
Without sparing Jiro a second glance, Sengoku turned and walked toward the three younger boys, who were now paralyzed with terror.
"S-stay back!" Saburo screamed, trying to scramble away, but his legs had turned to jelly.
"We're sorry! We're sorry, Sengoku! Please!" one of the lackeys sobbed.
Sengoku stopped in front of Saburo, looking down at him with eyes devoid of any human warmth. "I've met people like you before. You aren't sorry about what you did. You're just sorry that you're finished."
Before Saburo could scream, Sengoku struck. Three rapid, blurring strikes. Three choked gasps. Saburo and his lackeys crumpled to the ground, clutching their stomachs, instantly incapacitated.
Flicking his fingers, Sengoku attached three invisible chakra threads to the boys' collars. Like dragging dead dogs, he hauled them across the dirt and dropped them in front of Jiro, who was just managing to push himself onto his knees.
"Tell your brother exactly how this started," Sengoku ordered, his voice echoing in the quiet training ground. "Don't skip a single detail. Now."
Through tears and choked sobs, Saburo stammered out the truth. He confessed to trying to extort Sengoku, getting rejected, and repeatedly trying to jump him in the alleys to save his own bruised ego.
As Jiro listened to the pathetic, cowardly truth, his face flushed a dark, violent purple. He might have been a brute, but he had a basic sense of pride. The realization that he had been manipulated by his little brother into fighting a six-year-old over a bruised ego—and subsequently getting his ass handed to him—was overwhelmingly humiliating.
A mix of shame, rage, and a primal fear of the cold-blooded child standing over them boiled over. Jiro snapped his head toward Saburo, his eyes bloodshot. "You little shits! You used me?! I'll break your damn legs!"
The threat was half-fueled by genuine fury, and half a desperate performance aimed at Sengoku, checking to see if it would appease him.
Sengoku's expression didn't change a fraction. He just stared at Jiro, his silence loudly conveying: Be my guest.
A chill ran down Jiro's spine. Knowing he had to extinguish Sengoku's quiet wrath to save his own skin, Jiro gritted his teeth, raised his heavy boot, and brought it stomping down on the calves of the three boys.
Crack!
The sickening sound of snapping bone was instantly drowned out by their agonizing shrieks.
Breathing heavily, Jiro slowly looked up at Sengoku. He swallowed hard. "...My apologies. I didn't know the whole story."
Sengoku glanced at him, then down at the three boys writhing in the dirt. "Next time, I welcome the challenge," Sengoku said, his voice flat. "As long as you are prepared to pay the price."
Without waiting for a response, Sengoku turned his back on the pathetic scene and walked out of the training grounds, his shadow stretching long against the setting sun.
Watching him leave, Jiro shuddered violently. He finally understood that this second-year student wasn't just talented; he was a cold, calculating monster that should never be crossed again. Gathering what little strength he had left, Jiro hoisted his screaming brother onto his back and limped away with the two lackeys.
Walking through the quiet evening streets, Sengoku's heart rate slowly settled.
He didn't feel a shred of triumph. As he rubbed his faintly aching ankle, his mind was completely focused on the cold reality of the fight.
He needed to rethink his criteria for a whetstone. Fighting a near-graduate was incredibly dangerous. Today was a schoolyard brawl governed by the unwritten rules of taijutsu. But what if it had been a real fight? What if Jiro had drawn a blade or unleashed a C-rank ninjutsu? The raw difference in their physical stats and chakra capacities would have been insurmountable. His Puppet Shunshin wouldn't have been enough to save him.
If he wanted to test his limits without throwing his life away, he needed to find an entirely different kind of opponent.