"So, the principle is sound?" Ren feigned thoughtful consideration before pressing the issue. "Uncle Shinku, I attempted it earlier, but the results were… underwhelming. Could you help me diagnose the problem?"
Shinku's expression shifted into that of an instructor. "Strike the training post. I can't promise to solve it, but I can offer observations."
"Right." Ren moved to the worn wooden post, centered himself, and took a steadying breath. He focused his intent, drew his fist back, and threw a punch. Simultaneously, he willed a surge of chakra to erupt from the points of contact in his knuckles.
Thud.
A soft, dull impact echoed. The sturdy post quivered slightly, but no more than if struck by a determined child.
'Even his failures are telling,' Shinku marveled silently. In just half a day, Ren's command over his chakra had grown visibly more assured, his control finer. The boy was, unnervingly, beginning to approach a level of finesse that took seasoned shinobi years to cultivate. He suppressed another wave of astonishment.
"Let me share my analysis," Shinku began after a moment's observation. "The chakra release is indeed instantaneous, which is the correct trigger. However, the volume is insufficient, the force is diffuse, and the energy lacks cohesion. More critically…" He pointed at Ren's still-clenched fist. "You are subconsciously apprehensive about injuring your hand. The majority of the chakra you're releasing is being used defensively, to cushion the impact, not offensively, to amplify it. Your fist didn't hurt much, did it?"
Ren considered this. His knuckles were merely warm, not sore. It made perfect sense. He recalled scenes from the original narrative—Hyūga Neji repelling Kidōmaru's attacks with a continuous chakra emission from his palms. Chakra could absolutely be used as a shield. His own subconscious, faced with the unyielding wood, had prioritized protection over power.
Anyone punching a solid wall would instinctively hold back.
Understanding dawned, and a grin spread across Ren's face. "So you're saying my resolve—my killer intent—is lacking?"
It wasn't as simple as he'd hoped. More interesting.
"Then… once more!"
Ren reset his stance, his expression hardening. This time, he banished all thoughts of consequence. He wouldn't hold back. He would strike with full, destructive intent. His body coiled, and he drove his fist forward with all his might!
BANG!
A louder, sharper crack echoed. The next instant…
"Oww-ow-ow-OWCH!" Ren shook his hand violently, hopping on one foot as a bright, throbbing pain radiated from his knuckles up his arm. He grimaced, sucking air through his teeth.
Shinku stared, utterly speechless.
Where did this walking comedy sketch come from?
What did resolve have to do with brute-forcing a technique he didn't understand? He felt the need to retract, once again, his assessment of Ren's all-encompassing maturity.
"You… only absorbed the latter half of my critique, didn't you?" Shinku said, pinching the bridge of his nose. "This is not a technique mastered through sheer willpower. I don't even know how to perform it properly."
He sighed. "If you are serious about learning it, when Lady Tsunade—one of the Legendary Sannin—next returns to the village, I could petition for an audience. Perhaps she could offer you guidance."
It was, in essence, a secret technique, a pinnacle of chakra application. Self-taught mastery was the stuff of myth. For a talent like Ren, however, Shinku was willing to swallow his pride and seek out the expert. Surely the Slug Princess could be persuaded… possibly with a substantial monetary offering? Not for a formal apprenticeship, of course, but for a few pointed lessons.
"Lady Tsunade?" An image flashed in Ren's mind: blonde, formidable, and… impressive in more ways than one. As a transmigrator with a well-documented appreciation for capable older women, this was an excellent development. Meeting the iconic characters was a must, and Tsunade had ranked highly on his list of… admired figures in his past life.
"I have immense respect for Lady Tsunade," Ren said, his tone appropriately reverent. "Her guidance would be invaluable. But for now, I'd like to keep experimenting on my own. Who knows? I might stumble upon a breakthrough."
Shinku chuckled. "Suit yourself. Just don't break your hand. It's not worth a temporary victory." With a final, amused shake of his head, he left Ren to his devices, heading inside to start dinner preparations.
"Understood."
Ren didn't immediately resume pounding the post. Instead, he sat on the sun-warmed back steps, his mind whirring like a high-speed processor.
'Chakra control is the foundation, but the execution requires a specific methodology. "Insufficient impact force"… It's not just about releasing chakra at the moment of contact. It's about a concentrated surge, a micro-explosion of energy at the precise point of impact.'
He noted, not for the first time, the sharpening of his mental faculties since the Spiritual Pressure Aptitude enhancement. Calculations that would have required conscious effort before were now instantaneous. His analysis of the problem was swift and logical.
He theorized the technique was analogous to the "one-inch punch" of martial arts lore—generating devastating power from a negligible distance through perfect body mechanics and focused energy release. The principles overlapped. His brief, past-life dabbling in a martial arts gym had included drills on this very concept; he was far from masterful, but he understood the theory.
With a hypothesis to test, Ren dedicated himself to experimentation.
For the remainder of the afternoon, the backyard echoed with the sounds of focused effort. A cycle established itself: practice until his meager chakra reserves were depleted, sit and meditate to replenish them, then practice again. Each cycle was a minor refinement, an adjustment in timing, concentration, and intent.
Unconsciously, through this repetitive strain and recovery, the total volume of chakra he could hold and regenerate expanded noticeably. By his estimate, he now possessed enough to perform a low-level D-rank ninjutsu, perhaps with a little to spare.
Progress.
"I think… I'm beginning to grasp it," Ren murmured, his eyes narrowing in focus. He rose for another attempt.
He centered his chakra, feeling it pool in his core. Ignoring the already bruised and split skin on his knuckles, he threw another punch at the beleaguered training post. This time, his focus was razor-sharp: not on releasing chakra, but on channeling it, on creating a sudden, pressurized wave that would crest and break exactly upon impact.
BANG! CRACK!
The sound was altogether different—a solid, crushing report. The wooden post shuddered violently. A web of fractures erupted where his fist connected, and splinters flew. The post itself was knocked clean from its footing, skidding several meters across the dirt before coming to a rest against the garden wall with a heavy thud.
A fierce, sharp pain lanced through his fist. His knuckles were a mess of raw skin and welling blood. Yet, Ren barely registered it. His gaze was fixed on the displaced post, his heart hammering with exhilaration.
"I did it!" he whispered, then a broader grin broke through. "I actually did it, you magnificent bastard!"
It was crude. It was inefficient and self-injurious. But it was undeniable proof of concept. To achieve this level of tangible result after only half a day of dedicated trial and error… his upgraded aptitude was terrifying.
The thrill of success morphed into a more mischievous, anticipatory delight. A slow, somewhat arrogant smile curved his lips as he examined his throbbing, victorious fist.
"Hehehe…" he chuckled to himself, the sound low and plotting. "If I land a punch like that, Kurenai is going to be crying for a week, isn't she?"
"Eep!"
A small, involuntary squeak came from the corner of the porch. Kurenai, who had been covertly observing her rival's terrifyingly rapid progress, felt all the blood drain from her face. She had seen the post fly. She scurried out from her hiding spot, her earlier bravado utterly evaporated.
She rushed over and tugged desperately on Ren's sleeve, her red eyes wide with a mixture of awe and pure, unadulterated fear. "Ren! Ren! I surrender! The spar is off! I don't want to do it anymore! You're the older brother! You're definitely, absolutely, 100% the older brother!"
She looked on the verge of tears. What kind of monster trained like this? If that fist connected with her, she genuinely believed she would cry. Not just for a long time, but possibly forever.