Watching his parents leave, Shin sat quietly on the bed, carefully sensing the chakra he had just extracted as it slowly dissipated.
Chakra was not like internal energy or magic—it could not be accumulated at will. If it was not used after extraction, it would gradually return to the body.
Unless, of course, it was stored using special methods—such as Tsunade's Yin Seal.
Shin waited until the chakra had fully dissipated before immediately forming the Ram Seal once more and continuing the extraction process.
This was chakra cultivation.
Because chakra is extracted and consumed on demand, ninjas usually extract it before battle to ensure it is ready for immediate use.
The problem is that an enemy will never stand still and wait.
A ninja is not a hero. They do not talk about morality, nor will they give you time to prepare before deciding the outcome.
Ninjutsu is a profession built on efficiency.
Completing the mission is the highest priority, and to achieve that goal, any means are acceptable—ambushes, poison, kidnapping relatives for leverage. Those are all basic operations.
So if you spend time calmly extracting chakra in front of an enemy, the opponent's response will be simple: strike and end you.
With a ninja's attack speed, even a brief moment is enough to kill someone in nine different ways.
If a ninja wishes to possess true combat power, chakra extraction must be cultivated until it becomes instinct.
That instinct means no longer needing to carefully balance physical and spiritual energy—and certainly not needing hand seals. With a single thought, the chakra should form naturally within the body.
At the highest level, the body will even begin to synthesize chakra autonomously during normal activity.
The Yin Seal exists to collect and compress this autonomously produced chakra—chakra that would otherwise dissipate—allowing it to be released explosively during combat.
It is equivalent to possessing an enormous extra chakra reserve at no cost, granting a massive advantage… and even enabling eternal youth.
Legend had it that Tsunade did exactly this. Though already in her forties, she behaved like a young woman, her apparent age fluctuating between ten and thirty.
Extracting chakra again, Shin quickly discovered that after one successful attempt, the second was noticeably easier.
He no longer needed to cautiously adjust the balance between the two energies.
It was as if his body remembered.
The pathway for chakra synthesis was beginning to solidify, and the speed of formation increased slightly—though he still required the Ram Seal to assist.
Very good.
This would now become his nightly cultivation routine.
He would continue until chakra extraction became pure bodily instinct.
Once the chakra naturally dissipated again, Shin began a third extraction.
After repeating the cycle several times, he glanced at the alarm clock and stopped for the night—it was almost time for bed.
Since his rebirth into the ninja world, Shin's schedule had become relentlessly disciplined. He slept exactly on time every day, giving his body ample opportunity to recover and never allowing fatigue to carry over.
The next morning, he would rise on schedule as well, exercising without permitting even the slightest thought of laziness or oversleeping.
Stepping into the living room, he found that his parents had already gone to bed. Several empty wine bottles sat on the dining table.
Both of them were still in their twenties.
Ordinarily, a reunion after even a short separation would be more intense than a wedding night, filled with both physical and emotional "exercise."
Yet tonight, the master bedroom was completely silent.
It seemed that after learning their son was a genius, the couple had been a little too happy—and had accidentally drunk a few bottles too many. They were now sleeping soundly.
A ninja must remain vigilant at all times, which is why alcohol is listed among the Three Prohibitions.
For them to indulge like this, it was not just happiness—it was because this home was a harbor where they could finally let down their guard.
Humans are intelligent creatures prone to extremes.
Ninjas, wielding extraordinary power, are even more so.
The masterminds lurking in the shadows usually shared the same origin: they had lost too many younger brothers, lost their goddess, or lost their closest companions—until one by one, they became madmen.
A happy family is the cure for all of that.
Unfortunately, it is precisely what many ninja lack.
Shin quietly cleared away the empty bottles and snacks, tidied up the table, and prepared to wash up and sleep.
Returning to his room, he noticed there was still some time before bed. He sat by the bedside, silently practicing hand seal speed.
At present, he was still unsure what his future combat style would be.
He didn't yet know whether ninjutsu, taijutsu, or genjutsu suited him best—but regardless of the path, improving hand seal speed was never a mistake.
When his designated bedtime arrived, Shin extracted chakra one final time.
After sensing that his cells were beginning to tire, yet his body felt filled with power, he lay down and fell asleep the moment his head touched the pillow, allowing the chakra to dissipate naturally.
The biological clock he had cultivated over several years ensured immediate sleep.
Yet tonight, something was wrong.
He remained awake.
Unusually awake.
His senses felt sharper than ever.
This shouldn't be happening.
In this reborn life, his family was complete and warm. He lived each day fully, without mental exhaustion. Insomnia should have been impossible.
Was it excitement from successfully refining the chakra for the first time? Or was it related to the chakra dissipating within his body?
Unable to sleep, Shin decided to head to the study and look through chakra theory texts. Perhaps he could find an explanation there.
But the moment he tried to move, he realized something was wrong.
He couldn't move at all. His body felt as though it were imprisoned against the bed.
The sensation was strangely familiar.
And soon, a memory surfaced.
He had experienced something like this before—back in his previous life, just before the college entrance examination.
Back then, something similar had happened for several nights in a row.
His eyes could see clearly, yet his viewpoint was fixed. His body was completely immobile, and fear spread uncontrollably through his mind.
At the time, it had terrified him.
Later, he learned that it was merely sleep paralysis—caused by excessive stress, common during adolescence, and often described as the sensation of being "pinned down."
Because he had experienced it before and understood the cause, there was no reason to be afraid now.
Shin even calmly observed the familiar ceiling of his bedroom, finding the situation faintly interesting.
Then he realized—
This was not the same thing at all.
His body was indeed frozen, completely unable to move, and even his eyes could not turn.
But his perspective could move.
He could look anywhere he wished, freely adjusting his viewpoint—like a fixed camera that could rotate in any direction.
And then he saw it.
His own body lay asleep on the bed.
At that moment, it felt as though he were floating above himself.
What is this?
Soul separation?
Calm down.
Shin forced himself to think rationally.
This was the Ninja World, not his previous life. Here, the soul truly existed—and in many known forms.
The dead rested in the Pure Land and could be summoned through forbidden techniques.
Among the living, some could project their souls freely, while others experimented with dividing or manipulating consciousness. Even shadow clones could share awareness.
But all of those souls could move.
He could not.
He could only observe.
After reviewing everything he knew and finding no clear match, Shin shifted his focus outward, carefully studying the world from this unfamiliar perspective.
That was when he noticed the difference.
The room was still the same room. The world was still the same world.
Yet beyond it all, space itself seemed filled with an incredibly thin, omnipresent haze.
It was something impossible to see or sense from a physical viewpoint.
From this perspective, the haze flowed like countless ribbons, weaving through heaven and earth—faint whites, reds, greens, purples, cyans, and more, drifting endlessly.
What is this?
Shin focused his will and found that he could nudge the mist—just slightly.
He tried to draw in the most abundant color: red.
The instant even a trace touched his consciousness, an overwhelmingly violent presence surged toward him.
Danger. Instinct screamed.
He immediately severed the connection and expelled the red mist.
He could expel it on his own. That realization steadied him.
He tested the other colors next. All were dangerous, though different from the red—rather than attacking outright, they attempted to assimilate him.
Only the white mist behaved differently.
It seemed to be breaking him down—slowly, gently. Its power was weak, the process gradual, and still within tolerable limits.
Shin noticed something else.
When the white mist intertwined with his consciousness, it flowed downward—toward his sleeping body.
He watched carefully.
His physical body showed no abnormalities. Instead, his consciousness seemed to act as a filter, resisting the destructive aspect of the mist and guiding what remained into the body below.
As this happened, Shin continued thinking.
What exactly is this mist?
After reviewing everything he knew about the Ninja World, only one answer remained.
Natural Energy.
But… were there really so many kinds of it? That wasn't mentioned in any records he knew.
Could this be… something unique to me?
As a reincarnator, how could he not hope for an advantage?
After all, unfair advantages were practically a tradition in this world.
Bloodlines, inherited chakra, divine powers—some people were practically handed miracles. Others received gifts again and again, until there was nothing left to give.
Shin, on the other hand, had been reborn as an ordinary civilian.
No legendary lineage.
No special eyes.
No extraordinary body.
No mysterious entity sealed inside him.
For a time, he had even half-jokingly hoped for some hidden system or guiding voice.
Nothing answered.
So he studied.
He trained.
He relied on discipline bordering on obsession.
He had even prepared himself for the worst—ready to stake everything on brutal physical paths if talent failed him.
And now—
Now something had appeared.
Did this mean he could finally take it easy?
No.
The thought vanished as soon as it formed.
If he worked hard before gaining this advantage and stopped working hard after, then this gift would be meaningless.
On the contrary—
He would need to work even harder.
Just then, Shin felt his consciousness begin to weaken. If this continued, he sensed that he would dissolve entirely, becoming part of the white mist.
Without hesitation, he forcibly severed the connection.
The fatigue hit instantly.
With a single thought, his consciousness returned to his body on the bed—and he fell into deep sleep.
So this power was not something to be used casually. One mistake, one moment of carelessness, and the result could be irreversible.
Natural Energy was powerful.
But indulgence was dangerous. Too much of it—and one might never come back.