Becoming Kakashi's apprentice was undoubtedly the biggest turning point in Ren's life since his transmigration. It meant more than just gaining a powerful backer or a safe haven—it granted him access to advanced ninjutsu and elite combat training, opportunities most genin could only dream of.
Kakashi's home was worlds apart from Ren's cramped orphanage room. Though modest, it was a clean, tidy two-story house with a quiet courtyard. Kakashi assigned him a guest room and instructed him to stay indoors for the time being to avoid drawing Root's attention.
The next morning, before dawn, Kakashi dragged Ren from bed and led him to a secluded training ground on the village's outskirts.
"From today onward," Kakashi said, still half-asleep and lazily flipping through his ever-present copy of Icha Icha Paradise, "your training will be under my supervision alone." Despite his slouched posture and drowsy tone, his words carried absolute authority. "Forget those flashy eye techniques for now. We're starting from the basics."
The basics? Ren blinked in confusion.
Kakashi set his book aside and fixed Ren with a calm, assessing gaze. "Your chakra reserves are dangerously low, and your physical condition is poor. No matter how powerful your eye techniques are, they're useless if your body can't support them or your chakra runs dry after one use. Right now, you're building a castle on sand."
A chill ran down Ren's spine. Kakashi had struck the core of his greatest weakness. While the Infinite Eye Technique System granted him extraordinary abilities—copying, fusing, and deploying ocular jutsu—each use drained both chakra and ocular stamina. His fusion with the Illusionary Eye and the battle against Root the previous night had nearly emptied his reserves, leaving him exhausted and vulnerable.
"The foundation of all ninja combat lies in taijutsu, ninjutsu, and genjutsu," Kakashi continued. "And beneath all three is chakra—and the body that channels it. For the next month, your training will focus on one goal: expanding your chakra capacity, strengthening your body, and mastering precise chakra control."
"Yes, sensei!" Ren replied, his voice low but resolute, eyes burning with determination.
Kakashi gave a curt nod, pulled a scroll from his flak jacket, and tossed it to Ren. "This contains my refined chakra cultivation method—more efficient than the Academy's standard curriculum. It also includes basic physical conditioning drills and chakra control exercises like tree climbing and water walking. Study it yourself first."
With that, Kakashi retrieved his book, strolled over to a large tree, leaned against its trunk, and resumed reading as if Ren no longer existed.
Ren's lips twitched. As unreliable as ever…
But he understood. Kakashi wasn't neglecting him—he was teaching in his own way. A ninja's path must ultimately be walked alone; a teacher's role was to guide, not carry.
Taking a deep breath, Ren unrolled the scroll and began studying in earnest.
Kakashi's chakra refinement technique was exquisite. Though rooted in the same principles as the basic method, its nuanced approach to harmonizing spiritual and physical energy drastically reduced energy loss during cultivation, boosting efficiency. Combined with his active "Chakra Refining Acceleration Card," the results were astonishing—like pouring gasoline on a flame.
The physical regimen, however, was brutal. Weighted sprints, extreme push-ups, high-intensity sparring—it was a merciless push toward the body's absolute limits.
As for chakra control, tree climbing and water walking were non-negotiable fundamentals. Only through meticulous regulation could a ninja channel just enough chakra to their feet to generate adhesion or buoyancy—allowing them to scale vertical surfaces or walk across water without sinking.
"Looks like I'm going to be flayed alive this month…" Ren muttered with a wry smile, though his eyes gleamed with resolve.
Without hesitation, he began.
First: chakra refinement. He sat cross-legged and followed the scroll's instructions, circulating energy through his chakra network. Almost immediately, he felt his reserves grow at a noticeably faster rate. With the acceleration card active, the process felt like riding a rocket.
An hour later, his chakra had swelled to the peak of early-genin level—with faint tremors signaling an imminent breakthrough to mid-genin.
"Alright," he said, rising. "Time for physical training."
He stripped off his shirt, revealing a lean but defined torso, and moved to the pile of training weights. He strapped iron blocks to his back—thirty kilograms, at least.
"Ugh!"
The moment he lowered into his first push-up, his arms screamed in protest, trembling under the strain.
Gritting his teeth, he channeled chakra into his muscles to reinforce them and forced out rep after rep: one, two, three…
Sweat poured from his brow, carving dark trails into the dirt beneath him. His muscles burned as if doused in fire, each movement an agony.
But he didn't stop. He couldn't. Every drop of pain was an investment—every limit broken, a step closer to strength.
Fifty.
On the final rep, his arms gave out. He collapsed face-first onto the ground, gasping, every muscle quivering uncontrollably.
"Huff… huff… Not enough… nowhere near enough…"
Somehow, he dragged himself upright and staggered into the next drill: weighted frog jumps.
The sun climbed higher. On the training ground, only two figures remained—the silver-haired jōnin lounging beneath a tree with his book, and a sweat-drenched boy who refused to yield.
Kakashi appeared absorbed in his novel, but from the corner of his eye, he watched Ren's relentless efforts. A flicker of quiet approval passed through his visible eye. Not bad… for a genin.
Talent mattered—but in the shinobi world, it was willpower and relentless effort that truly determined how far a ninja could go.
This disciple might just surprise him yet.
Ren was deep in the fundamentals of chakra control when the system chimed again.
[Ding! New Mission Issued: The Craving for Bloodline Limits!]
Mission Objective: The foundation determines the ceiling—but bloodline limits shape the pinnacle of ninja power. Powerful ocular techniques require potent "nourishment" to fuse and evolve. Within one month, obtain partial or complete data on at least three distinct bloodline limits.
Rewards: Slight increase to maximum eye power; Beginner-Level System Shop unlocked; 1 random eye technique skill scroll.
Failure Penalty: Random loss of one previously copied bloodline limit.
Three bloodline limits?
Ren's pulse quickened. The timing couldn't be better. Though his Illusionary Eyes held immense potential, their current capabilities were still limited. To evolve, they needed the essence of stronger bloodlines.
Konoha was a treasure trove of such power. The Uchiha's Sharingan. The Hyūga's Byakugan. The Aburame's symbiotic insect techniques—technically not a kekkei genkai, but extraordinary nonetheless. The Inuzuka's ninken-enhanced combat. And who knew what other hidden lineages lurked beneath the village's surface?
Of these, the Hyūga, Aburame, and Inuzuka clans were the most accessible.
Looks like I'll need to "befriend" these clans outside of training hours, Ren mused.
But first—foundation. Without it, even the rarest bloodline was wasted.
Over the next several days, Ren threw himself into Kakashi's brutal regimen with single-minded focus.
Days were spent mastering extreme physical conditioning and precision chakra control—tree climbing, water walking, endurance under cascading falls. Nights were reserved for accelerated chakra refinement, using system-issued techniques and time-acceleration cards to expand his reserves at an unnatural pace.
The results were staggering.
In just ten days, his chakra reserves shattered the genin bottleneck, surging to mid-chin level. His once-lean frame now thrummed with coiled, explosive strength. Tree-walking and water-walking had been conquered within a week; now, he could sprint across rivers and scale sheer cliffs as if they were flat earth.
Even Kakashi was taken aback. He'd expected this progress to take a month—not ten days.
"It seems I underestimated your willpower… and your potential," Kakashi said, closing his ever-present Icha Icha. He watched Ren train beneath the roaring waterfall, a rare flicker of pride in his visible eye. "You've built a solid base. Now… let's move to something practical."
Practical? Ren's eyes lit up. He vaulted down from the falls and dashed toward his sensei, anticipation crackling in his stance.
But Kakashi didn't unveil a jutsu. Instead, he asked, "What do you know about the Hyūga clan's Gentle Fist?"
Ren blinked—then understood. Gentle Fist wasn't just taijutsu; it was surgical warfare. By channeling chakra directly into an opponent's chakra pathways, it could rupture organs or seal tenketsu, cutting off chakra flow entirely. Nearly impossible to counter without sensory perception.
"I know it targets internal systems and pressure points," Ren replied honestly. "It's said to disable even elite shinobi with a single strike."
Kakashi nodded. "Correct. Paired with the Byakugan's 360° vision and X-ray sight, it's devastating. But even without it, the core principles—precision, redirection, and chakra finesse—are invaluable."
He extended a single finger. "Attack me."
Hesitant but obedient, Ren lunged, fist crackling with chakra.
An inch from Kakashi's finger, the jōnin flicked his wrist—just a whisper of motion. Ren's strike dissolved like mist. His own momentum betrayed him, and a subtle nudge sent him stumbling backward.
"See that?" Kakashi retracted his hand. "That's deflection—a core Gentle Fist principle. Minimal force, maximum imbalance. Redirect their energy, and they defeat themselves."
A spark flared in Ren's eyes. This… this could revolutionize my close combat!
"Teach me," he said, voice firm.
Kakashi's eye crinkled in a smile. "The full art is a Hyūga secret. But I can share fundamentals—stances, chakra-threading, basic tenketsu strikes, and redirection theory. How far you go depends on you."
"Thank you, sensei!" Ren bowed deeply, heart racing. Even fragments of Gentle Fist would be a game-changer.
The next phase of training began immediately. Stances. Footwork. Fingertip chakra concentration. Pressure point targeting. Flow redirection.
The demands on chakra control dwarfed even water-walking. Every movement required microscopic precision—channeling chakra to the exact millimeter of fingertip, releasing it at the perfect microsecond to disrupt meridians.
It was grueling. Exhilarating. Perfect.
What astonished Ren most? His Illusionary Eyes—evolved from the Sharingan—revealed chakra pathways in vivid clarity. When Kakashi demonstrated a technique, Ren didn't just see the motion; he saw the chakra weaving through meridians, pooling at critical nodes.
His comprehension accelerated exponentially.
Within days, he'd mastered basic stances and executed simple tenketsu strikes with growing accuracy. He was far from mastery—but the promise was undeniable.
At the same time, Ren hadn't forgotten the system's mission. During breaks from training, he occasionally wandered around the village, scanning for potential "targets."
Soon, his attention turned to Hyūga Neji—a prodigy of the Hyūga branch family who often practiced the Gentle Fist alone in the training grounds.
Ren didn't rush in recklessly. Instead, he concealed himself at a distance and activated his Illusory Eye, meticulously observing Neji's every movement and the subtle fluctuations of chakra in his activated Byakugan.
[Ding!]
[Detected bloodline limit: Byakugan (Hyūga Neji). Analyzing… copying…]
[Copying progress: 1%… 5%… 10%… Copy successful!]
[Acquired: Byakugan (partial data)]
[Ding!]
[Detected unique taijutsu: Gentle Fist (Hyūga Neji). Analyzing… copying…]
[Copy successful!]
[Acquired: Gentle Fist (partial technique data)]
"Success!" Ren whispered, a surge of excitement coursing through him. Even though the data was incomplete, he'd already fulfilled one-third of his mission. More importantly, the copied Gentle Fist techniques could immediately enhance his own understanding and execution of the style.
His next targets were the Aburame and Inuzuka clans.
Though both clans kept a low profile, Ren soon found an opening. He "accidentally" crossed paths with Kiba Inuzuka—walking his ninken, Akamaru—and Shino Aburame, whose high-collared coat and quiet demeanor did little to hide the faint hum of kikaichū insects hovering nearby.
Through a brief but deliberately friendly exchange (in which Ren did most of the talking), the system activated unnoticed.
[Ding!]
[Detected kinjutsu variant: Beast Human Clone (Inuzuka Kiba). Copy successful!]
[Acquired: Partial data on Inuzuka clan cooperation ninjutsu]
[Ding!]
[Detected secret technique: Parasitic Destruction Insect Technique (Aburame Shino). Copy successful!]
[Acquired: Partial data on Aburame chakra-insect symbiosis]
[Ding!]
[Mission: "The Desire for Bloodline Limits" – Completed!]
[Rewards unlocked:]
Slight increase to maximum eye power
System Shop (Beginner Tier) now accessible
Random Eye Technique Skill Scroll ×1 deposited in system storage
Relief and exhilaration filled Ren. The boost to his eye power sharpened his vision—literally—granting him a faint but unmistakable clarity, as if he could now perceive the hidden layers beneath surface reality.
The opening of the System Shop sparked eager curiosity. What rare items might it hold?
Without delay, he checked the random scroll.
[Congratulations, Host! You have obtained: "Illusory Eye – Light of Insight"]
[Description: A derivative ability of the Illusory Eye. Consumes eye power to temporarily enhance perception, piercing low-level genjutsu and disguises, and significantly improving chakra flow detection accuracy.]
"This is perfect!" Ren realized. Enhanced chakra flow perception would complement Gentle Fist flawlessly—allowing him to pinpoint tenketsu with far greater precision.
He immediately began integrating the skill.
Just as his strength grew and his mission concluded, however, trouble arrived uninvited.
That evening, after finishing his training, Ren was walking back toward Kakashi's residence when a group blocked his path.
At their head stood a richly dressed youth with a lifted chin and contemptuous eyes. Ren recognized him instantly: Takeuchi Ryūya, cousin of the Takeuchi Ryōsuke he'd defeated weeks earlier. Rumor had it Ryūya was a chūnin and a rising name among Konoha's younger generation.
Flanking him were several other shinobi—clearly his loyal followers.
"You're Ren?" Ryūya looked him up and down as if inspecting spoiled goods. "So you're the orphan who dared injure my brother?"
Ren's expression darkened slightly. Revenge, then.
Not wanting unnecessary conflict, he replied evenly, "He provoked me. He got what he deserved."
"Hmph! Bold words for a gutter rat," Ryūya sneered. "I don't care about excuses. You struck a member of the Takeuchi family—now you'll pay. Today, I'll teach you that some people aren't meant to be crossed by common trash like you."
His cronies grinned, stepping forward to encircle Ren.
A cold glint flickered in Ren's eyes. Some people never learn.
Since they'd come looking for a lesson… he wouldn't disappoint.
Perfect.
Let's test my new Gentle Fist—and Light of Insight—on you.