Night had fallen over the mountain forest.
Suppressing the terror gnawing at his heart and the suffocating pressure bearing down on him, Tanjiro gritted his teeth, fueled by a desperate thirst for strength, and swung his blade at Ron.
"Water Breathing, Fourth Form—"
Tanjiro launched a rapid series of slashes, as fierce and relentless as crashing waves. But against this tide-like assault, Ron merely flickered through the shadows, the withered branch in his hand flashing like a streak of gray lightning. Each time, the branch pierced precisely into the weak points of Tanjiro’s strikes, forcing him into a corner.
While casually parrying and countering, Ron spoke, his voice calm but firm:
"Water Breathing demands a mind as still and clear as a tranquil lake. Only then can you wield its true power."
Tanjiro swung his Nichirin Blade with all his might, struggling to fend off Ron’s attacks that poured down like a violent storm.
He stumbled back, step by step.
The clothes on his body were being shredded by the impossibly fast, unpredictable movements of Ron’s withered branch, each swing slicing through fabric with terrifying precision.
From the sidelines, Kanao whispered, a hint of confusion in her voice,
"Why... why can’t he cut it?"
"Because he hasn’t even landed a hit yet..."
Shinobu answered softly, her wide purple eyes brimming with shock and wonder.
She had never witnessed swordsmanship before.
It was like a wild, free-spirited dance across the heavens—
unpredictable, unbound, so masterful it transcended the limits of human imagination.
It was... simply inconceivable.
Ron’s branch struck Tanjiro’s shoulder sharply, sending him sprawling backward. Only then did Ron finally ease up, ceasing his relentless barrage.
But in Tanjiro’s eyes, a glimmer of light flashed—
Gritting his teeth against the searing pain in his shoulder, he stomped the ground, steadying his stance. In a single explosive motion, he hurled himself forward, pouring every ounce of strength into a desperate, high-speed thrust toward the towering figure who loomed over him like a nightmare.
Water Breathing, Seventh Form—
With a swift flick of his wrist, Ron swung the branch lightly.
In that instant, the very air before him rippled like a pond disturbed by a stone, several shimmering blue whirlpools materializing out of thin air.
Tanjiro’s all-out thrust collided with them—
only to be ensnared, dragged off-course by the swirling currents as if he had plunged into a mire.
His eyes widened in shock as he watched—
his Nichirin Blade, which had been aiming straight for Ron’s chest, was now helplessly pulled to the side.
Ron lashed out with a simple kick.
Tanjiro’s body was sent hurtling backward like a ragdoll, smashing into the trunk of a massive tree with a heavy thud.
His blade slipped from his hands as he slumped down, his face twisted in pain.
Forcing his eyes open, Tanjiro stared at Ron in disbelief.
"That just now... what was that...?"
"Feels familiar, doesn’t it?"
He looked at Tanjiro and said calmly,
"That too is Water Breathing. But the move itself—was something I created."
Tanjiro’s eyes widened even more.
"You... created your own technique?"
Kanao and Shinobu exchanged startled glances.
Even they couldn’t hide their amazement.
"Technique is not a dead thing," Ron said, walking back toward the campfire. He tossed the nearly shattered branch—bearing the scars of their fierce bout—into the flames.
He turned to Tanjiro, who sat slumped at the base of the tree, still staring at him with awe.
"When you reach the point where you can forge your own techniques, you’ll have truly grown strong," Ron said with a relaxed smile.
"But for now, you need to focus on mastering Total Concentration Breathing."
He turned his gaze to Shinobu and grinned.
"I’ll leave that part to you, Miss Shinobu."
Caught off-guard, Shinobu blinked, confused.
Over the next two days—
The group traveled while continuing their training.
During the day, Shinobu took charge of Tanjiro’s physical conditioning, teaching him methods to quickly master Total Concentration Breathing.
Ron would unleash a controlled surge of killing intent, engaging Tanjiro in intense sword duels.
"No fear of death! A heart tough as iron! Don’t allow even a shred of fear toward me!"
Tanjiro was sent flying through the air.
"Stop thinking! Let instinct take over!"
"Y-Yes, sir!" NovelHub
"What was that hesitation just now?!"
Tanjiro once again crashed backward, his head embedding itself into a thick tree trunk.
"Calm your mind like still water! When using Water Breathing techniques, you must be completely free of distractions!"
A few brutal days passed.
Tanjiro was battered and bruised from head to toe—but his growth was undeniable, visible even to the naked eye.
At the start, he could barely endure twenty moves against Kanao. Now, he was holding his own in sparring matches against her.
As for Total Concentration Breathing, he was nearly at full mastery.
Even Shinobu was astonished at how quickly his strength was rising.
As they neared the location of Tanjiro’s assigned mission, a letter arrived for Shinobu, a response from the leader of the Demon Slayer Corps.
Standing beneath the tree, she tilted her head up to look at Ron, who sat casually on a high branch, gazing into the distance.
"The Master has invited you to visit the Demon Slayer Corps headquarters."
"Oh yeah...? When do we leave?"
"I’m ready anytime. How about you? Do you want to wait until he finishes his mission?" Shinobu glanced over at Tanjiro and Nezuko.
"No need. The demon lurking here isn’t strong. Tanjiro can handle it himself. Besides..."
Ron flipped down from the tree in one smooth motion.
"That kid needs more real combat experience if he’s going to grow."
Ron called over Tanjiro, who was busy with his physical training, and explained the situation.
"Eh? Mr. Ron and Miss Shinobu are leaving already?" Tanjiro exclaimed in surprise.
"Yeah. I’ve taught you about all you can handle for now. What you need next is real battle experience and your own insights."
Ron crossed his arms over his chest, looking at him steadily.
"Next time we meet, I hope you’ll be a little stronger. When that day comes, I’ll teach you the techniques of the Sun Breathing."
Tanjiro’s eyes welled with deep gratitude as he looked at Ron.
"Mr. Ron... I will never forget your kindness! Thank you so much!!"
Seeing Tanjiro bow a perfect ninety degrees toward him, Ron rubbed his ear awkwardly and sighed.
"Alright, alright, no need to get all formal."
Then he turned his gaze toward Nezuko, who was quietly standing by Tanjiro’s side. Ron bent down and gently patted her head and said with a warm voice,
"See you next time, Nezuko."
Shinobu and Kanao also said their goodbyes to Tanjiro and Nezuko.
Under the veil of night, the three figures disappeared into the darkness.
Tanjiro stood there, staring longingly at their retreating silhouettes, his heart filled with emotion.
"Mr. Ron... He’s such a kind and powerful person... I wonder if I’ll ever become someone like him..."
Nezuko, biting down softly on her bamboo muzzle, gazed up at the departing figures and quietly patted her own head.
On the road to the Demon Slayer Corps headquarters—
Shinobu finally asked the questions she had held back while they were with Tanjiro.
How could Ron, a human, possess the ability to control ice?
How did he know so much about events that happened four hundred years ago?
To all of this, Ron simply answered with one word—