The spar continued for nearly twenty exchanges.
Kurenai refused to surrender despite the widening gap between them. Her kunai repeatedly flickered toward Ren's throat, shoulders, and joints, each attack flowing smoothly into the next. Whenever he moved beyond her reach, she used shuriken to restrict his movements before closing the distance again.
Her style was fast, precise, and dangerous.
Unfortunately for her, Ren had already seen through its rhythm.
On the twentieth exchange, Kurenai stepped forward and thrust her kunai toward his chest. It appeared to be a direct attack, but Ren noticed the slight tension in her shoulder and understood that the thrust was merely a feint.
The real attack would come from below.
Ren shifted half a step to the side. As expected, Kurenai abruptly reversed her grip and slashed upward, aiming for the inside of his arm.
This time, however, Ren didn't retreat.
His hand moved like a striking snake, slipping past the kunai and closing around her wrist. Before Kurenai could adjust, he twisted her arm outward and struck the back of her hand with two fingers.
A sharp numbness spread through her wrist.
The kunai slipped from her grasp.
Ren caught the falling weapon before it reached the ground, spun around her guard, and tapped the blunt end of its handle against her ribs. His free hand followed with two controlled strikes—one against her shoulder and another stopping a fraction away from her throat.
Kurenai froze.
Ren's borrowed kunai rested against her neck.
After twenty exchanges, Ren disarmed Kurenai with his bare hands and decisively ended the spar.
"You lost," he said.
Kurenai stared at the kunai for a moment before releasing a long breath. The tension left her body, and her shoulders sagged with exhaustion.
"I know."
Ren withdrew the weapon and returned it to her. He then spent a moment replaying the fight in his mind, carefully sorting through the flaws he had noticed in her movements.
"Your footwork is good, and you're skilled at changing direction midway through an attack," he began. "But you rely too heavily on speed. Whenever someone disrupts your rhythm or forces you into a direct clash, your balance becomes unstable."
Kurenai listened seriously despite still breathing heavily.
"You also expose your wrist whenever you reverse your kunai grip. Against an ordinary opponent, the movement is probably too fast to punish. Against someone who can follow your hands, it becomes an obvious opening."
Kurenai glanced down at the wrist he had struck and slowly nodded.
Ren continued, "Your combat style should focus on agility, precision, and attacking from unexpected angles. Don't compete directly with opponents who are stronger than you. Force them to turn, make them divide their attention, and strike only when they reveal an opening."
"So I should concentrate on my strengths instead of trying to compensate for everything at once?" Kurenai asked.
"Exactly. You can still improve your physical strength, but don't build your entire fighting style around it." Ren considered his next words before adding, "If circumstances allow, try some light weight training. It should help strengthen your arms and legs without slowing you down."
Kurenai raised an eyebrow. "Light weight training?"
"Yes. Emphasis on light," Ren warned. "Excessive weight training at your age might interfere with your physical development. It would be troublesome if you stopped growing."
He was talking about her height.
Nothing else.
Kurenai narrowed her eyes as though she suspected his explanation wasn't entirely innocent, but Ren maintained a perfectly composed expression.
Before she could question him, he returned to the more important subject.
"Your greatest talent is still genjutsu. That should remain your primary focus, while taijutsu serves as a secondary discipline."
Kurenai's expression became thoughtful.
"You may even be able to combine them," Ren said. "Use subtle illusions during close combat—distort an opponent's perception of distance, hide the direction of a strike, or make your movements appear slightly faster or slower than they truly are. A moment of uncertainty is enough to decide a taijutsu exchange."
A fighting style that fused genjutsu with taijutsu could turn Kurenai's greatest strength into a lethal close-range weapon.
Her genjutsu talent might appear unimpressive when compared with someone like Itachi Uchiha, but that comparison was unfair. Once Itachi possessed the Mangekyō Sharingan, his genjutsu stood close to the summit of the entire ninja world.
If Kurenai properly developed her natural gifts, she could potentially reach a level comparable to an accomplished Uchiha with a fully matured three-tomoe Sharingan.
That alone would be terrifying.
Countless ninja possessed little or no resistance to genjutsu. Against such opponents, one successful illusion could end the battle before they even realized it had begun.
"I understand." Kurenai gave Ren a grateful nod. "I'll try developing my techniques in that direction."
Her legs were still slightly unsteady from the fight, so she moved toward the edge of the clearing and sat beneath a tree to recover.
Rin stepped forward to replace her.
Although they were teammates, Ren had to admit that Rin's taijutsu was significantly weaker than Kurenai's. She lacked both physical strength and refined technique, and the hesitation in her movements made the problem even more noticeable.
Her technical weaknesses could be corrected through proper instruction and repeated practice. Strength, however, was more complicated.
Given enough time, Ren could help Rin follow a path similar to the one Sakura Haruno would take in the future: mastering the Strength of a Hundred Seal and combining it with chakra-enhanced strength. That route could transform a medical ninja into a terrifying close-range fighter capable of shattering the ground with a single punch.
The problem was time.
Such techniques required exceptional chakra control and years of preparation. Even with Rin's talent, she would probably need at least two or three years before achieving meaningful results.
By then, the battle at Kannabi Bridge might already have occurred.
The thought cast a shadow over Ren's mind.
He couldn't afford to build Rin's survival plan around an ability that might mature too late to save her. For now, he needed to focus on techniques that could improve her chances of survival immediately.
One step at a time, he reminded himself.
The Strength of a Hundred Seal was far too advanced to rush. In a few days, he could find an opportunity to teach her the Water Clone Technique and Wild Water Wave. Neither was overwhelmingly powerful, but both would give her more options for keeping enemies at a distance, creating openings, and escaping dangerous situations.
The Water Formation Wall would have to wait.
Ren hadn't completely mastered that technique himself. Teaching Rin an unstable or incomplete version would do more harm than good.
There was also his altered Transformation Technique.
Perhaps he could teach her a variation that incorporated additional physical characteristics. It was worth testing, though he couldn't guarantee that someone without his system-enhanced understanding would be able to reproduce the results.
As for his unique Substitution Technique, that was out of the question.
Even if he discovered a way to teach it, Ren had no intention of spreading the technique. One person using such an unreasonable ability was already more than enough.
After guiding Rin through several exchanges and correcting the most obvious problems in her stance, Ren allowed her to rest.
Asuma immediately stepped forward.
"Come on, Ren!" He raised his fists, his eyes burning with competitive spirit. "I won't concede so easily this time."
Before the last word had completely left his mouth, Asuma stomped against the ground and surged forward.
His right fist tore through the air with a low whistle, aimed directly at Ren's face.
Ren raised his forearm.
Their limbs collided with a dull thud, and the force of Asuma's punch drove Ren half a step backward. Ren used the movement to disperse the impact while his left hand shot forward to seize Asuma's wrist.
Asuma reacted instantly.
He dropped his elbow, knocking Ren's hand aside, while his free hand reached into his ninja-tool pouch. Steel flashed as he drew a kunai and slashed diagonally toward Ren's chest.
Ren's right hand swept behind his shoulder.
His short sword left its sheath with a metallic whisper. Instead of blocking with the blade, Ren rotated the weapon and caught Asuma's kunai against the metal ring at the end of the hilt.
Clang!
Sparks burst between them.
Asuma twisted his wrist and tried to wrench the kunai free, but Ren stepped inside his guard. Their shoulders collided, and both immediately shifted their footing, fighting for control of the distance.
Kunai and short sword flashed through the clearing.
Their movements accelerated with every exchange. Steel scraped against steel, sparks scattering across the ground as the sound of their weapons echoed through the trees.
Kurenai and Rin watched from the sidelines, their attention fixed on the rapidly shifting battle.
Then Ren saw something move.
It was barely noticeable—a slight tremor in the leaves at the edge of his vision. There was no wind strong enough to cause it.
Someone was hiding in the nearby thicket.
Ren's expression sharpened.
He abruptly poured strength into his weapon and forced Asuma back a step. In the same instant, his body disappeared in a swirl of leaves as he used the Substitution Technique to retreat.
Ren reappeared several meters away, short sword raised and gaze fixed on the shadows beneath the trees.
"Who's there?" His voice cut across the training ground. "Come out!"
Asuma immediately forgot about their interrupted duel. He turned toward the thicket and raised his kunai, while Kurenai and Rin sprang to their feet.
"Someone was watching us?" Asuma asked.
No one answered.
The training ground became unnaturally quiet. Sunlight shifted across the grass, and the shadows beneath the trees seemed to deepen.
Then the leaves rustled.
A slender figure slowly emerged from the thicket with an embarrassed expression.
The newcomer appeared to be seven or eight years old, slightly younger than Ren and the others. He had mildly curly black hair, large dark eyes, and a dark-blue, short-sleeved outfit bearing a familiar clan emblem.
Like Ren, he carried a short sword across his back.
The boy stopped several paces away and bowed apologetically.
"I'm sorry. I wasn't trying to spy on you," he explained. "I was passing nearby when I heard the sound of fighting. I became curious and wanted to observe your spar so that I could learn from it."
"An Uchiha?" Asuma asked, immediately recognizing the red-and-white fan displayed on the boy's sleeve.
The boy straightened. "Yes. My name is Shisui Uchiha, and I haven't officially become a ninja yet."
Ren's eyes flickered.
So it really was him.
The unexpected spectator was Shisui Uchiha—the future wielder of Kotoamatsukami.
Ren knew that Shisui was close in age to Obito, yet he had never encountered him at the Ninja Academy. Perhaps Shisui had never enrolled, or perhaps the Uchiha clan had arranged a different form of education for him.
Some children born into prominent ninja clans received most of their training within their own families. Hanabi Hyūga would follow a similar path in the future. In the eyes of certain traditional clans, the Academy's standardized education could never compare with techniques passed down privately through generations.
Whatever the reason, meeting Shisui here was completely unexpected.
It was also an extraordinary opportunity.
Compared with Obito—who currently knew little beyond the Great Fireball Technique—Shisui was already likely to possess a much broader foundation. He was a descendant of Kagami Uchiha, and despite being slightly younger, he had probably learned several clan techniques.
More importantly, Shisui possessed outstanding talent in genjutsu.
If Ren could learn even one or two useful techniques from him, the encounter would be worthwhile. His current system catalogue didn't contain a single proper genjutsu ability.
In Ren's eyes, the shy child standing before him was practically a walking treasure vault.
Shisui bowed once more and began to step away. "I apologize for interrupting. I'll leave now."
"Wait."
Shisui stopped and looked back.
Ren lowered his short sword but didn't sheathe it. "You said you came here to observe and learn. Watching from a distance won't teach you much. Why don't you practise with us instead?"
Shisui appeared startled by the invitation.
He glanced at Ren, then toward Asuma, Kurenai, and Rin. Uncertainty flickered across his face.
"Wouldn't that be inappropriate?" he asked. "You were already in the middle of your training."
"It's fine. We're only sparring." Ren gave him a reassuring smile. "We're all comrades of Konoha. There's no need to be so formal."
He then turned toward Asuma.
"What do you think?"
Asuma was visibly annoyed that his duel had been interrupted just as it was becoming interesting. However, he wasn't about to contradict Ren in front of a member of the Uchiha clan.
Besides, he was curious.
He wanted to know how strong this younger Uchiha actually was.
"Fine." Asuma lowered his kunai and stepped toward the edge of the field. "Go ahead."
Shisui looked between them once more. Realizing that the invitation was sincere, he licked his lips and stopped refusing.
His right hand reached over his shoulder and closed around the hilt of his short sword. The embarrassment in his eyes faded, replaced by intense concentration.
"In that case, Senior…" Shisui drew the blade a few inches from its sheath. "Please guide me."
"All right." Ren took a slow breath and settled into a sword stance. "Come."
Shisui drew his short sword.
The instant the weapon entered his hand, his entire presence transformed.
The shy, apologetic child disappeared.
A fierce sharpness radiated from his body, and the air around him seemed to tighten. Shisui bent his knees slightly, lowering his center of gravity like a leopard preparing to pounce.
Ren's fingers closed more firmly around his sword.
They stared at one another across the clearing.
One heartbeat passed.
Then Shisui moved.
Whoosh!
His figure blurred into a dark line and crossed the dozen meters between them almost instantaneously. His speed was so extraordinary that several fading afterimages remained behind him.
"So fast!" Rin and Kurenai exclaimed together.
Shisui's short sword was already in motion.
The blade slipped forward like the tongue of a venomous snake, its angle treacherous and ruthlessly precise. Instead of targeting Ren's sword arm or chest, it pierced toward the vulnerable space beneath his ribs.
Ren's pupils contracted.
His body reacted before conscious thought could catch up, relying on instincts sharpened through countless sparring sessions with Kakashi. His wrist snapped sideways, and his short sword carved a precise diagonal arc through the air.
Clang—!
The collision of steel erupted across the training ground.
Sparks exploded between the crossed blades, illuminating Shisui's focused eyes for a fraction of a second.
Then the force of the impact surged down Ren's arm.
His wrist trembled.
The ground beneath his heel cracked as he was forced to brace himself, and genuine surprise flashed across his face.
This speed was already astonishing—but how could a child Shisui's age possess such overwhelming strength?