Mount Momoyama, true to its name, was covered with peach trees stretching across the mountains.
It was late autumn now. Unfortunately, there was no chance to witness the dazzling spring scene of peach blossoms painting the sky pink, nor to taste the plump, juicy peaches Zenitsu was always talking about.
Asuka walked alone along the winding mountain path, fallen leaves rustling softly beneath his feet.
Originally, out of goodwill, he had wanted to invite Zenitsu to come to Momoyama with him to consult Kuwajima Jigoro. It would also give the boy a chance to return and rest for a couple of days.
However, the child seemed to carry some shadow about returning to Momoyama. He would rather stay at the estate to undergo intensive training than come here.
After reaching a flat clearing halfway up the mountain, he finally arrived at the dojo of Thunder Breathing.
It was completely different from the large training grounds at the Hayama cultivation facility, which were grand in scale and crowded with disciples. Before him stood only a simple wooden hut.
In front of the hut lay a carefully leveled patch of sand. Several thick wooden stakes had been driven deep into the ground, their surfaces covered with countless blade marks of varying depths.
Not far away stood a massive ancient tree that looked as though it had been struck by lightning. Its entire trunk had turned a deep black.
So this was the Momoyama dojo? It looked quiet enough. Quite to his liking.
"Hey! You brat over there! What are you sneaking around looking at?!"
A loud shout filled with energy suddenly rang out behind him, making Asuka's ears buzz.
Immediately afterward, a short figure rushed over in a flurry.
He wore a yellow-brown kimono, and his wooden prosthetic leg struck the ground with sharp, rapid clacking sounds.
His wrinkled, scar-covered face carried a mischievous smile like that of a child. With slightly cloudy eyes, he looked Asuka up and down.
"This is private property. We don't sell peaches here, and we don't take apprentices!"
Asuka quietly observed the former Thunder Hashira of the Demon Slayer Corps, sensing the aura within his body.
The old man had restrained his presence to the extreme. If not for the razor-sharp rhythm of his breathing, one might mistake him for an ordinary old man with no threat at all.
"I am Asuka of the Demon Slayer Corps. Pleased to meet you."
Asuka gave a slight bow.
"Oh? So you're the Storm Hashira that the Kasugai Crow mentioned, the one coming here to train?"
Kuwajima Jigoro narrowed his small eyes. Leaning on his wooden cane, he stepped closer, his gaze sweeping back and forth between the blade at Asuka's waist and the brand-new haori he wore.
"I thought someone who could slay an Upper Rank demon and become a Hashira would at least look like a sturdy giant like Gyomei. Didn't expect you to still be just a kid."
He gave a strange chuckle, though it sounded a bit like he was grumbling to himself in annoyance.
"Tch... the Mist Hashira, the Serpent Hashira... why are all the youngsters these days so ridiculously strong at such a young age? When will our Zenitsu finally become a Hashira..."
"Senior?"
Interrupted from his muttering by Asuka, Kuwajima let out an embarrassed snort.
He turned around and asked curiously, "So what exactly can you train here? You already have your own Breathing style and fighting methods. Aren't you worried about biting off more than you can chew?"
He spoke earnestly.
"You should know that whether it's strength or techniques, more isn't always better. Sometimes even if you only know one or two techniques, as long as you train them to the absolute peak, they can still become unstoppable killing moves!"
Kuwajima Jigoro firmly believed in this principle.
"I understand. I only want to reference the characteristics of Thunder Breathing. In the end, it's still about forging my own path."
Asuka answered decisively.
"Besides, I want to restore Sun Breathing."
Kuwajima had already heard about this in a letter from the Master. Though it sounded unbelievable, he had prepared himself mentally.
He examined Asuka again.
He noticed that the boy's eyes were extremely pure. There was none of the arrogance that often came with early fame. Instead, there was a calm steadiness.
He had seen this kind of gaze in many people before. But very few could maintain such patient curiosity even after becoming a Hashira.
Still, he wanted to test the young man's temperament a little more.
The strange old man chuckled mischievously and pointed his cane toward a long-neglected patch of barren land behind the dojo.
"It's late autumn. Before the first snow falls, I have to turn over all that soil so I can plant medicinal herbs for next spring."
"You. Go turn that soil."
Medicinal herbs? That was obviously just a barren patch of land. The excuse had clearly been made up on the spot.
Asuka glanced at the barren slope, then at the old man's back.
"Alright."
He removed his haori and Nugata, picked up the hoe beside the dojo, and walked toward the cold hillside.
For the next three days, Kuwajima Jigoro truly seemed to treat Asuka as free labor.
He dragged out a rattan chair and sat at the edge of the slope. Holding a chipped coarse clay bowl in his arms, he drank steaming brown rice porridge while pointing and shouting instructions at Asuka.
"Hey! Kid! Are you slaughtering pigs or something? That swing was way too strong! The soil needs to be loosened, not smashed apart. You're splitting the ground in half!"
"Too slow! The essence of Thunder Breathing lies in that single instant! At your speed, before you even draw your sword, a demon would have plucked every hair off your body!"
"Tsk tsk... youngsters these days are as fragile as paper. Back when this old man trained in Momoyama, work like this only took five minutes... and that crybaby may be hopeless, but his talent for labor is far better than your wooden head!"
Whenever he mentioned that crybaby, a trace of warmth and faint pride always flashed across Kuwajima's deeply wrinkled face.
So what if he could only use the First Form? Didn't he still help the Hashira kill an Upper Rank demon?
Zenitsu would definitely make something of himself.
Asuka did not grow impatient because of the mockery.
He gradually realized that Kuwajima's taunts were meant to shake his will. And under the old man's guidance, this so-called soil turning had gradually transformed into a kind of sword-form training.
Following Kuwajima's instructions, he compressed the power of his body to the extreme, then released it in a single explosive instant through his legs and arms.
If mastered, this technique could combine with bursts of spiritual pressure during battle to achieve instant kills.
By the evening of the third day, the once-barren slope had become evenly turned and soft.
"Old man, the soil's finished."
Kuwajima Jigoro slowly walked over and opened the dojo door. He stomped his wooden prosthetic on the ground without any intention of inspecting the field.
"So-so. Come inside. Don't stand out there getting cold. If you catch a chill, I'll have to waste medicinal herbs on you."
Inside the dojo, the firewood in the hearth crackled.
Kuwajima Jigoro sat cross-legged across from Asuka. His expression had become extremely serious, carrying the bearing of a former master.
"Listen carefully, Asuka. Thunder Breathing is different from other Breathing styles. What it pursues is the ultimate burst of power, the ruthless squeezing of the body's limits."
"Beyond that, it also requires the resolve and courage to draw your sword and charge forward no matter how powerful the enemy may be."
"Because of that, swordsmen who use Thunder Breathing are more likely to be injured or lose limbs. It is brilliance bought with life itself."
He picked up a pair of fire tongs and drew a straight line in the ashes of the hearth.
"Among my disciples, there was once someone with very high talent... Unfortunately, he could never understand this point. He could never draw the straightest line. That's why he could never master the First Form."
Kuwajima's voice lowered, and a trace of pain flashed in his eyes.
"As for the other one..."
His tone softened considerably, filled with the satisfaction of having found a treasure.
"He only knows the First Form. He cries and says he can't do it. Every day he wants to run away."
"But I know that he worked incredibly hard to train the First Form to a level that even I admire."
"That child's name is Zenitsu. He will definitely become a Thunder Hashira even greater than me."
"Now, watch closely."
Asuka listened quietly.
Suddenly, Kuwajima Jigoro drew his sword.
In that instant, Asuka felt as if the air in front of him had been cut open.
There were no flashy sword forms.
A golden flash faster than the limits of human sight streaked across his vision.
Slash!
A perfectly straight blade of sword energy crossed three meters in an instant, precisely slicing through a wooden stump on the opposite side of the hearth.
"This is First Form: Thunderclap and Flash."
Kuwajima sheathed his blade in one smooth motion.
"It is the foundation of all Thunder Breathing techniques, and also its final destination. If you can comprehend this move, then your understanding of lightning will already be complete."