In this era, there were few people Jin was familiar with, and most of them had no chance to learn Basic Internal Energy.
After all, if he took out a secret technique and told seasoned ninjas—who had already established their combat abilities—that it could enhance their strength, they'd hardly believe him.
Only a select few were gullible enough to buy it.
He popped a piece of pastry into his mouth. The sweetness spread across his tongue, filling his heart with a sense of happiness.
"So sweet."
Just as he reached for another piece, a cat's paw pressed down on the back of his hand, stopping him.
A pair of blue feline eyes stared intently at Jin, and the cat let out a meow.
"Where's your promise?"
"Where's your stretcher?"
"What nonsense are you talking about?"
The kitten, Xiao Miao, lunged at him with a flurry of wild scratches, only to be effortlessly pinned down on the table by Jin's single hand, where it continued to struggle.
"Fine, fine. A year's supply of cat treats. I'll buy them tomorrow."
Hearing this, Xiao Miao finally gave up its struggle and allowed Jin to cradle it in his arms, stroking its fur.
Even cats knew how to bargain these days.
Life wasn't easy.
With a casual toss, Jin sent Xiao Miao tumbling to the floor, but it landed gracefully on its feet.
"Go play. You can stay here for now."
Jin's home had no summoning beasts—aside from him, not even a ghost could be found. Letting a cat stay was no big deal.
Xiao Miao licked its paw, seemingly indifferent to whether it had heard him or not.
Heading upstairs, Jin opened the storage room in his house.
"Less than a year left. I need to boost my combat power."
He had to prepare for the battlefield that might await him in the future.
His eyes scanned the shelves filled with neatly arranged scrolls—ninjutsu techniques.
It was only natural for an elite jonin's home to have a sizable collection.
A small portion consisted of techniques earned through missions, such as the Shadow Clone Jutsu. The rest fell into two categories: one was the Uchiha clan's collected techniques, and the other was a diverse array of sealing techniques.
Yet, these paled in comparison to Konoha's vast ninjutsu repository.
Although the Uchiha clan's collection was far more extensive than what was here, Konoha's archives held copies of all of them.
Beside the bookshelf stood a round wooden table with six ninjutsu scrolls arranged in a circle.
These were the techniques Jin had spent a long time developing through deduction.
He hadn't been idle during his restrictions. His eyes skimmed over the words on the scrolls:
Shave, Paper Drawing, Finger Gun, Iron Body, Cat Language, Basic Internal Energy.
Four of the Six Powers from the world of pirates had already been realized. However, Storm Leg and Moonwalk were impossible to achieve without the ability to externalize chakra—unless his physical strength increased tenfold.
Most of his time had been spent perfecting these four techniques, which was why he had only now begun teaching Basic Internal Energy to others.
To impart knowledge to others, he needed a solid foundation himself—otherwise, he'd just be a charity case.
Only when he developed stronger techniques would he consider sharing these.
"Looking back, it really hasn't been easy."
To complete the first four techniques, he had to meticulously explore their feasibility, draft theories, and submit them for deduction—only to fail repeatedly.
It was almost as grueling as writing a university thesis.
Fortunately, he'd succeeded in the end, and these techniques became his safeguard in this world.
As for Cat Language, he had spent time interacting with cats, collecting their sounds, and deducing the technique.
Basic Internal Energy was the foundation of everything he had now.
"Based on my current strength, I should be able to handle an average chunin. But if it's a jonin—even a special jonin—I'd likely die."
This was all theoretical, of course. He had never actually fought a chunin, but on paper, his combat power was sufficient.
"My advantage lies in close combat, but ninjas specialize in mid-to-long-range attacks. I need a way to counter long-range ninjutsu."
"Lightfoot."
Jin had made up his mind. Speed was power—that had always been his belief.
If he couldn't win, he could at least outrun his opponents. What he needed was something like Lingbo Weibu, enhanced tenfold by chakra.
If he combined Shave to increase his movement range and distance, no one would be able to catch or hit him.
He already had some theories in mind but hadn't yet completed them.
"Using Paper Drawing for perception, Shave for movement, and incorporating the Five Elements and Eight Trigrams."
In his past life, he had been led into superstition for a time, which drove him to study texts like the Book of Changes and the Eight Trigrams. Though his memories were fuzzy, he could extract the knowledge through deduction.
First, he summoned the deduction text box. With a thought, the vague concepts of the Eight Trigrams and Book of Changes appeared on it.
Then, he pulled out some movement-based ninjutsu scrolls from the shelf and researched the range of large-scale techniques.
He needed to organize all of this, refine the details, finalize his ideas, and input them into the text box.
"Deduce."
The results would come soon.
[Deduction failed.]
Uchiha Jin: (╯°□°)╯
"Honestly, are you some university professor in disguise, forcing me to write a thesis?!"
"Do I have to run a plagiarism check too, you bastard?!"
This system, which felt like it was designed to make him write papers, was utterly suspicious!
"What's missing?"
Jin began reviewing his thesis—no, the compiled theories.
Just then, his pupils contracted into tiny black dots before quickly returning to normal. A look of delight spread across his face.
"Kushina actually broke through?!"
…
Rewinding time slightly.
After seeing Namikaze Minato off, Kushina leaned halfway out the window, resting her chin on her hands as she watched the raindrops fall outside.
"But why is my underling so girly and dumb?"
She was lost in her own frustrations. Minato had left in a daze, his face wooden and prone to blushing.
Then there was that infuriating Uchiha—no words were needed for him.
"Neither of you will ever find girlfriends."
Kushina wrinkled her nose in disdain.
One was girly, the other had a sharp tongue.
After tidying up the table, she returned to her room.
This house had belonged to Mito. When the Nine-Tails was sealed inside Kushina, Mito passed away, and the place became her home—though it didn't feel like one.
"I'm just an outsider here."
Kushina sat on the bed, immersing her mind into her own body.
Perhaps this was the only way to quiet her restless thoughts.
The ninjutsu she had obtained from that Uchiha induced a state of tranquility, gradually settling her chaotic mind.
Following the instructions of Basic Internal Energy, she focused on the dantian.
There, her chakra had woven itself into an egg-like shape, occupying her lower abdomen. Every wisp of chakra she produced was drawn into it—even the chakra leaking from the Nine-Tails.
Moreover, the Nine-Tails' chakra, which was normally difficult to control, became entirely hers once it entered the egg.
As a result, the originally blue egg now glowed golden.
"But isn't that fox red?"
Kushina was puzzled. Occasionally, she could enter the seal within her body and see the foul-tempered fox trapped in what looked like a sewer.
Now, she could do so more easily.
Inside the golden egg, an intricate sealing formula dominated the center. A red dot continuously released red chakra, which then transformed into gold.
At first, the red chakra had been abundant, but now only a trickle seeped out.
Still, even that trickle had turned her golden chakra egg into something solid.
According to Basic Internal Energy, as chakra condensed, the initial sealing formula—woven from chakra threads—would first become a transparent glowing egg, then an opaque, solid one like the current state.
"I think I've completed the first stage."
Kushina pondered.
The first stage was essentially a process of accumulating chakra, which wasn't particularly difficult. Anyone with chakra could achieve it.
The challenge lay in the second step.
"Using chakra to seal the body's chakra pathways, while drawing chakra from the egg to construct the sealing formula."
However, Basic Internal Energy didn't specify how much chakra was needed, and that Uchiha hadn't mentioned it either.
"It must require a lot."
Kushina frowned slightly and focused her mind on the center of the chakra egg.
Darkness enveloped her as she found herself in a vast space—a massive stone prison surrounded by mountains.
From the shadows of the prison, a pair of crimson eyes opened, glanced at the little girl who had appeared, and then closed again.
Kushina wasn't afraid. She strode up to the seal's gate and saw the enormous fox lying on the ground, seemingly asleep.
She kicked the bars twice, producing loud clangs.
"Hey, big fox, wake up! Lend me some chakra."
Kurama didn't even lift an eyelid. His voice was clear as he replied:
"No."
If it had been anyone else, he might have agreed—letting the jinchuriki lose control, break the seal, and free him.
But this little brat, after learning that damned technique, had started absorbing his chakra.
What kind of ninjutsu was that? He had never heard of such a bizarre technique—it was practically a natural enemy of the tailed beasts!
Mito had been bad enough, occasionally lashing out at him when she was in a foul mood. But this girl? She was outright robbing him!
"Stupid fox, lend it to me!" Kushina's hair flared up in anger at the refusal.
Kurama turned around, presenting his backside to her—a clear dismissal.
This only infuriated Kushina further.
"Stupid fox, you're lending it whether you like it or not!"
Three chains shot out from her back, slipping past the bars and lashing toward Kurama.
Before the fox could react, the chains struck his hindquarters, eliciting a pained howl.
"YOWL!"
Back in her body, Kushina's face flushed as she glanced guiltily at the ceiling and muttered an apology.
"Sorry, I didn't mean to. But you were the one who turned your back on me."
(Kurama: I hereby declare you the cruelest jinchuriki.)
There was no time to dwell on it now. A massive surge of chakra erupted from the chakra egg, so much that the egg couldn't absorb it all fast enough.
She quickly steadied her mind and focused on controlling the chakra. Fortunately, the egg's suction was strong enough to prevent the Nine-Tails' chakra from leaking out.
Otherwise, people outside would surely notice.
"Use chakra to seal all the chakra pathways in the body."
"The second realm of Basic Internal Energy—Body-Opening Realm—complete!"
(End of Chapter.)