The next morning, the atmosphere on Mount Momoyama was a little strange.
The sun rose as usual, and birds still sang on the branches, but Zenitsu's usual crying and screaming had disappeared.
He was avoiding Uesugi Sasuke.
Like a mouse that had seen a cat.
At mealtimes, he held his bowl and huddled in the corner farthest from Sasuke.
When sweeping the courtyard, he only dared move his broom outside Sasuke's field of vision.
He dared not look into Sasuke's eyes, afraid that black eye would suddenly turn a terrifying blood-red.
Jigoro Kuwajima saw it all but said nothing.
The old man seemed especially silent that day, and even the wrinkles on his face seemed deeper than usual.
Morning training began in that oppressive atmosphere.
"The foundation of Thunder Breathing lies in instantaneous explosive power."
Kuwajima's voice echoed through the empty training hall, more serious than usual.
"And that explosive power comes from your legs. But your legs are only the endpoint of that power. The true core lies in your waist and abdomen!"
As he spoke, he demonstrated the movements himself.
"Feel it! Feel how every breath fills your lungs with the power in the air, then sinks into your lower abdomen. Then, through the twisting of your waist and abdomen, lash that power out like a whip!"
Zenitsu did his best to imitate him from the side.
He inhaled hard, holding his breath until his face turned red, then sharply twisted his waist. His footing slipped, and he fell flat on his back with his limbs in the air.
"Idiot!"
Kuwajima's cane struck Zenitsu's head without mercy.
"Feel it with your brain, not brute force! Is your waist a piece of wood? Can't you turn it?"
Zenitsu clutched his head, his eyes brimming with tears, and said aggrievedly, "But Master, I can't feel it... This power, this whip-I don't understand any of it..."
Kuwajima's mustache trembled with anger. He was about to scold him again when he suddenly stopped.
He glanced at Sasuke, who stood on the other side of the training hall and had not said a word the entire time.
Sasuke simply watched in silence, his face expressionless.
But at an angle Kuwajima could not see, a trace of crimson quietly emerged in the pitch-black pupil of his right eye, and a single black tomoe began to rotate slowly.
Sharingan, activated.
At that instant, the entire world was redefined in his vision.
Master Kuwajima was no longer simply an old man.
He became a precise anatomical model composed of countless lines of energy and muscle tissue.
When his master began demonstrating again, Sasuke saw it.
He clearly saw how, as Kuwajima inhaled, the expansion of his lungs engaged the intercostal muscles, turning his chest cavity into a perfect resonating chamber.
He saw how the inhaled power sank along the spine, gathering in the waist and abdomen to form a rapidly spinning vortex of energy.
He saw how, when his master assumed the sword-drawing stance for [First Form: Thunderclap and Flash], power traveled like a fine yet resilient spiderweb, passing precisely from the core of his waist and abdomen into the quadriceps of his thighs, then along his taut calves and all the way into his toes.
The speed of blood flow, the trembling of muscles, the angles of bones, the transmission of nerve signals...
Those abstract concepts that had once sounded utterly incomprehensible and profoundly mysterious were now mercilessly dismantled, analyzed, and quantified beneath his Sharingan.
They became sets of perfectly clear data and unmistakable energy pathways.
So this was the essence of Thunder Breathing.
It wasn't some vague, intangible "feeling."
It was a set of biomechanical formulas for generating force with the human body, refined to the utmost precision.
The world was reconstructed before his eyes.
The corners of Sasuke's mouth rose ever so slightly, almost imperceptibly.
"Master... I'll try again. I'll definitely get it this time..."
Looking miserable, Zenitsu climbed off the floor once more, ready to try again.
"Enough."
A cold voice interrupted him.
Sasuke slowly walked over. The crimson in his eye had already faded, returning to its normal black.
He walked to the center of the training hall and said calmly, "Master, let me try."
Zenitsu froze, then curled his lip.
Was he kidding? I've been learning this for so long and still can't do it. This monster has only been learning for a few days. Could he really pull it off?
He must be trying to show off in front of Master.
Jigoro Kuwajima said nothing. He merely looked at Sasuke with an extremely complicated gaze and nodded.
Sasuke did not look at anyone.
He slowly closed his eyes.
In his mind, every detail of Master Kuwajima's demonstration recorded by the Sharingan replayed in slow motion, like scenes from a film.
The angle at which his lungs expanded.
The timing of the exertion from his waist and abdomen.
The degree of tension and relaxation in his muscles.
Not the slightest deviation.
Three seconds later, Sasuke abruptly opened his eyes.
He crouched slightly and leaned forward, resting his loosely curled right hand on the hilt of the wakizashi at his waist.
This was the stance.
The opening stance of [First Form: Thunderclap and Flash].
Zenitsu stared, stunned. Why did this stance feel... exactly like Master's?
Then Sasuke began to breathe.
"Hooo-"
It was a deep, prolonged inhalation.
With that breath, his entire presence changed.
If Zenitsu's breathing was a stream that flowed in fits and starts, Sasuke's was a great river surging without end.
A visible current of air spread outward from him in every direction.
Dust in the training hall swirled gently into the air.
At that moment, Jigoro Kuwajima's pupils abruptly contracted to pinpoints.
What had he seen?
He saw that Sasuke's body was like a precisely calibrated machine.
The core strength in his waist and abdomen instantly twisted together into a single cord. Powerful force traveled along his spine, and the muscles in his legs ignited one after another in a perfect rhythm.
Not the slightest unnecessary movement.
Not the slightest waste of power.
Textbook.
This was a textbook-perfect gathering of power, something only a master who had spent decades immersed in Thunder Breathing and worked every detail into his very marrow could possibly achieve.
Sasuke did not dash forward.
He did not even draw his blade.
He merely completed the stance for gathering power, then slowly released his breath and straightened.
But the training hall fell into a deathly silence.
Zenitsu gaped, staring blankly at Sasuke before looking at his own hands and feet. His expression shifted from disdain to shock, then bewilderment, before finally turning utterly ashen.
Why...
Why could he do something so well after seeing it just once, when I still couldn't do it after practicing so hard for so long?
Sasuke paid no attention to Zenitsu's nearly shattered pride.
He looked at Kuwajima and asked calmly, "Master, is this right?"
Jigoro Kuwajima did not answer.
The old man simply stared fixedly into Sasuke's black eyes, as though trying to find that fleeting flash of blood-red within their unfathomable darkness.
This was no longer something that could be explained by the word "talent."
This was "seeing through."
It was the power to directly "see" through everything another person had spent a lifetime learning, then "plunder" it-a power bordering on that of gods and demons.
He did not know whether it was a god or a demon that had bestowed those eyes upon Sasuke.
A long while passed.
Only then did Kuwajima avert his gaze and hoarsely utter two words.
"...Very good."
Before you continue