In the end, the edge of the blade stopped one centimeter above Haruki's head—so close it was practically brushing his scalp.
"Huff… huff…"
Haruki gasped for breath. Sweat beaded across his forehead, his face flushed, his heart pounding nearly twice as fast as normal. His arms, still holding the blades, trembled uncontrollably.
This was the backlash from his earlier burst.
Even with the temporary boost in comprehension pushing his chakra control to the absolute limit of what he could currently manage, sustaining such a prolonged, high-intensity output still placed an enormous burden on his body—bordering on actual injury.
On top of that, Fukai's explosive power was simply overwhelming. Every collision had brutally tested Haruki's arms. He could already feel multiple muscle strains forming.
"Sensei is too strong… Even at full output, I couldn't force you back a single step."
After steadying his breathing, Haruki sealed both blades back into the storage seals in his bracers, openly marveling at his teacher's strength.
Whether it was raw power or speed, Fukai far surpassed him. Just now, Fukai hadn't even used ninjutsu—he had relied solely on chakra-enhanced physical strength, yet effortlessly neutralized Haruki's relentless barrage.
More than a hundred strikes, and Haruki hadn't managed to injure him in the slightest. When Fukai counterattacked, Haruki was crushed and driven back as if facing an unstoppable tide.
As expected of a jōnin who specialized in nintaijutsu.
And as expected of the man who would one day become the Eight-Tails' Jinchūriki.
Of course… the biggest issue was simply that Haruki himself was still too weak.
Right now, his combat strength was roughly comparable to Rock Lee during the Chūnin Exams—without opening the Eight Gates.
And that was only during a burst state.
From start to finish, the fight had lasted less than a minute.
Not even three minutes.
Once his chakra ran dry, relying on physical conditioning alone, he had no way to contend with Fukai.
Fukai glanced at his own blade—its edge now nicked and jagged like a small saw—and sighed quietly. Even so, he was clearly pleased with his student.
"Your burst just now was extremely powerful. It's enough to contend head-on with a taijutsu-specialist chūnin. To have reached this level at ten years old is remarkable.
"Choosing long blades to partially compensate for your lack of long-range ninjutsu was a wise decision. Especially against opponents like puppet users with mechanical bodies—this approach is far safer."
At ten years old, this level of strength could already be called genius-tier. If not for his limited chakra pool preventing sustained output, Haruki would possess genuine chūnin-level combat power.
Of course, raw strength was only part of what defined a chūnin. Tactical command ability mattered just as much—and that wasn't something that could be judged yet.
"I only achieved this by putting in several times the effort of a normal person," Haruki said, shaking his head with a wry smile.
This was the gap in physical aptitude—something that couldn't be endlessly bridged through sheer effort alone.
In this world, talent determined the ceiling, while effort merely decided the floor.
Without Ōtsutsuki blood, one didn't even qualify to become the Ten-Tails' Jinchūriki.
"You're still too young. Your body hasn't fully matured—focusing on raw strength isn't suitable right now. Your blades and your sword style emphasize thrusts over slashes, which makes them better suited for speed-based bursts.
"Next, I'll guide you in Lightning Release nature transformation. Once you master it, you can use Lightning chakra to stimulate your nerves and muscles, increasing explosive speed.
"Speed-based stimulation places far less strain on the body than pure strength output. It's far better suited to your age and build.
"After that comes real combat. You have almost no actual battle experience. Your fundamentals are solid, but rigid—you need extensive real combat to bring your swordsmanship to life."
Fukai laid out a clear plan for Haruki's training going forward.
Just then, a figure flashed beside them.
"I told you so Fukai. Haruki really is a rare genius."
It was A.
He had arrived long ago and had watched the entire fight.
Though it had lasted barely a minute, he found it fascinating—and genuinely surprising.
He had always known this kohai was talented, but he'd assumed his brilliance lay in weapon design and unconventional ideas.
Who would have thought his talent in training and combat was just as frightening?
A had seen clearly how Haruki improved during the fight. Even when facing Fukai's active offense, his responses grew increasingly smooth.
If not for the vast difference in strength—and the complete depletion of chakra—Haruki might have lasted even longer.
"Bro A!" Haruki greeted him.
"Come on. I've already prepared medicinal baths and medical-nin support for you," A said, throwing an arm around Haruki's shoulder as he led him out of the training field.
This visit had been specifically to take his kohai to the medicinal baths.
Fukai followed as well. He still wanted to discuss Haruki's future training path—especially Haruki's own thoughts about his long-term direction.
---
"…Isn't this the Yotsuki clan's secret medicinal bath?"
Standing before three massive wooden tubs filled with dark liquid, Fukai was visibly shocked.
He had used Yotsuki clan body enhancement baths before. They were extremely effective and excellent for repairing hidden injuries.
But even he had enjoyed them fewer than ten times.
They were simply too expensive—one bath cost over a million ryō. Even with family backing, repeated use was unsustainable.
More importantly, this was a closely guarded Yotsuki clan secret, later refined by the Second Raikage using medicinal knowledge from multiple Kumogakure clans. Its value was immeasurable—an undisclosed art shared only within the Yotsuki clan and the Raikage line.
And yet, A was bringing Haruki here.
Something was definitely off.
"This is even more advanced than the version you used back then," A said proudly. "It's the medicinal bath we use to temper our hand-blades. My father's Hell Stab was refined with this bath over many years."
This was the true perfected version. The earlier full-body refinement baths were merely simplified derivatives.
The cost, however, was staggering.
Each of these three tubs cost ten million ryō. In the past, the Yotsuki clan could only afford small batches, using them solely to temper the hands for their inherited hand-blade technique.
The Yotsuki clan's core secret art was forged through near self-destruction—tempering the body until their hands became blades as sharp as lightning. Only then could Lightning Release: Lariat reach its true, unstoppable power.
That was why Lariat, despite being classified as a C-rank technique, possessed power rivaling even S-rank jutsu, capable of breaking through a tailed beast's defenses.
Building upon that foundation, A's father developed the even stronger Hell Stab, repeatedly suppressing the rampages of the Eight-Tails and Two-Tails.
And now, A had extravagantly prepared ten times the usual dosage—enough to temper the entire body.
"Haruki," A said, turning to Haruki, who was staring at the tubs with barely concealed excitement.
"This is a secret Yotsuki clan medicinal bath. Each tub costs ten million ryō—three tubs, thirty million total. The medicinal effect lasts for a full month, and you can bathe once per month. Think you can handle it?"
He was openly tying Haruki's future benefits to this arrangement.
In other areas, Haruki was impressive—but when it came to making money, he was downright terrifying.
His current income was already shocking. In the future, it would only rise further—surpassing the village's total revenue was only a matter of time.
After discussing it with his father, this bold plan had taken shape.
Using Haruki's financial power, the three of them would push their physical conditioning to the absolute limit—at the very least, strengthening their bodies as much as possible.
In the past, the Yotsuki clan's limited resources forced them to restrict this precious medicinal bath to hand refinement.
Now, they could go further.
Once the body was fully enhanced to its extreme—and then combined with nintaijutsu—the resulting power was almost unimaginable.