If Shimizu could one day possess chakra reserves as monstrous as Naruto's, then he wouldn't need to worry about conservation at all. He could unleash his techniques freely, without restraint—filling the battlefield with overwhelming, high-powered ninjutsu.
A walking bombardment unit. A one-man map-clearing weapon.
Kekkei Genkai? Dōjutsu?
All of it could be blasted into dust.
Just imagining it was exhilarating.
A little daydreaming never hurt anyone—it was good for the mind, after all.
…Of course, that was all it could ever be. A fantasy.
Naruto's absurd chakra reserves came from both his innate talent and the presence of the Nine-Tails. That kind of "build" was utterly unique—there simply wasn't a second person in the entire shinobi world who could compare. It was a gap Shimizu knew he would never bridge in this lifetime.
As for increasing his own chakra…
Ever since he had exhausted the vitality he'd drawn from the Uzumaki lineage, the bottleneck had become painfully obvious.
Worse still, as time passed, the rate of his chakra growth slowed to a crawl.
Especially over the past year, the increase had been almost negligible.
Even now, he was still quite some distance away from the immense chakra reserves once possessed by the Sannin.
Once possessed.
Because during his last conversation with Jiraiya, Shimizu had sensed something faint but undeniable—
Jiraiya's chakra had already crossed into the Kage level.
Among the Sannin, Tsunade of the Senju clan had vanished without a trace, while the genius Orochimaru had sunk deeper into his experiments and forbidden techniques. Ironically, it was Jiraiya—the so-called underperformer—who had overtaken them both, becoming the first to truly step into that threshold.
Was it simply a case of hard work overcoming talent?
Or had Jiraiya always been the real genius?
From Shimizu's perspective, the gap between them—purely in terms of chakra—had only widened over the past year.
And this was while Jiraiya split his time between writing novels, gathering intelligence, and… collecting "inspiration."
Meanwhile, Shimizu had been training relentlessly.
So why was the difference growing larger instead of shrinking?
If things continued like this—if he relied solely on steady accumulation—then even by the time Konoha Year 60 arrived, when the main story would truly begin…
No.
He didn't even need to look that far ahead.
The Uchiha massacre.
The night of the Nine-Tails' attack.
Those looming events alone were enough to crush him under their weight.
Minato and Kushina's relationship was steadily deepening. At this rate, marriage—and a child—would come within the next two or three years.
And two or three years…
Would pass in the blink of an eye.
The excitement from developing his new technique, from successfully fusing a Kekkei Genkai—it all faded instantly.
In its place rose a suffocating sense of urgency.
A pressure that whispered of impending disaster… and death.
Chakra.
That damned bottleneck.
There seemed to be no solution.
Talent… or a Tailed Beast.
Aside from those, what options were there?
…Kisame?
The "tailless Tailed Beast"?
Samehada.
Kisame's massive chakra reserves were largely due to Samehada, which could devour the chakra of others, store it, and then feed it back to him.
And Shimizu—
He had Samehada too.
Something inside him that clearly possessed a similar "devouring" property. After all, it had once consumed the poison within his body.
So then…
Could it also absorb chakra?
Store it for his own use?
By the time dawn broke, Shimizu—despite having trained through the entire night—felt no trace of fatigue. Instead, he was brimming with restless energy, eager to test this newfound possibility.
He needed a subject.
Someone to experiment on.
…
By the time the morning was half gone, after dragging Shisui into a series of tests, the result was…
Nothing.
Absolutely nothing.
Shimizu left with a frown, while Shisui remained behind, utterly confused, staring blankly into space.
"How can this be…? It clearly worked before…"
Shimizu replayed the memory in his mind—the night Samehada had devoured the poison.
The toxin had first entered his body.
Only then had Samehada begun to consume it.
So that meant…
The enemy's chakra would have to enter his body first.
In other words—
He'd have to take the hit.
Shimizu's expression stiffened.
Wasn't that basically asking him to get beaten first?
That wasn't a method.
That was suicide.
With his current physique, taking a high-level ninjutsu head-on would be enough to finish him off.
No, this won't work.
He needed another approach.
Shimizu suddenly realized just how little he actually understood about Samehada. Faced with that gap in knowledge, he found himself at a complete loss, unable to identify any clear breakthrough.
With no other options, he turned his thoughts toward the fragments of memory he still had from the original story, digging through everything he could recall about Kisame and Samehada—any detail, no matter how small. He vaguely remembered that Samehada was originally a weapon, that Kisame could merge with it, and that he could even summon sharks…
But the Samehada inside him?
Calling it a weapon would be completely inaccurate. It existed as a form of water-nature chakra—a living energy within his body.
Fusion… that was an immediate no.
Looking cool was a lifelong commitment, after all.
Summoning?
He hadn't even signed a summoning contract—how could he possibly summon sharks?
…Wait.
Samehada had always been inside him, unable to manifest externally.
Could it be… a matter of spatial restriction?
The thought sparked something.
It was worth trying.
Without hesitation, Shimizu bit his finger, formed hand seals, and attempted to use the Summoning Jutsu to call forth the Samehada within him.
Once.
Twice.
Three times…
Every single attempt resulted in the same outcome.
A cluster of small snakes appeared instead.
"…Seriously?"
For a moment, Shimizu even felt the urge to go back and cancel his contract with Ryūchi Cave altogether.
No, that couldn't be right.
There had to be a way to control it. Otherwise, how did shinobi with multiple summoning contracts manage to call forth exactly the creature they intended each time?
There had to be a trick to it.
And so, another entire day slipped by as Shimizu immersed himself in the mechanics of the Summoning Jutsu.
By sunset, just as he began to grasp a faint thread of that elusive feeling, he finally succeeded—
By sheer chance, he summoned something new.
A strange fish, roughly the size of a small dog.
It looked vaguely like a shark, but its head was disproportionately large, its jagged teeth unnervingly sharp. Its body was covered in countless dark-blue barbs that glinted faintly in the fading light.
The creature flopped energetically on the ground, thrashing against the dirt.
Shimizu froze.
He had actually summoned it.
This… was the Samehada inside him?
Slowly, he reached out and touched it.
The moment his fingers made contact, a strange, indescribable sense of familiarity surged through him.
It felt as though this creature was a part of him.
Or perhaps… another form of his own existence.
But there was one glaring problem.
Shimizu could feel his chakra draining rapidly, far faster than usual. After an entire day of experimentation, his reserves were already low—and now, maintaining Samehada's presence in the physical world was consuming it at an alarming rate.
He carefully gauged the speed of the depletion.
Even at full capacity, he wouldn't be able to sustain this state for more than ten minutes.
The cost was staggering.
"…You've got to be kidding me."
His original goal had been to use Samehada to compensate for his lack of chakra.
And now?
He had summoned something that devoured chakra even faster.
Not only had he failed to solve the problem—he had made it worse.
So then… what was the point of summoning it?
It should be able to absorb chakra, right?
As for merging with it—
Shimizu crushed that thought the instant it formed.
Absolutely not.
No way.
Still, before he could proceed with further testing, his body suddenly gave out. His vision blurred as his strength drained away, and he collapsed heavily onto the ground.
With a soft puff, the summoned Samehada vanished.
His chakra had been completely exhausted.