One Piece: With Sign-in System

Ron looked at the bewildered Tanjiro and smiled.

"Those two demons Kibutsuji Muzan sent after you... I'm afraid they were targeting you specifically. Most likely, when he caught a glimpse of your earrings, it stirred up his memories of the fear he once felt — back when he was almost killed by Yoriichi Tsugikuni. Thinking you might be his descendant, he decided to eliminate you before any trouble could arise."

"I see… So that's how it is."

Tanjiro stood there, dumbfounded.

A man with unfathomable abilities…

A man whose strength ran so deep it felt endless…

A man who even knew secrets not recorded anywhere in the Demon Slayer Corps' four-hundred-year-old history…

Who exactly was he?

Butterfly Shinobu watched Ron out of the corner of her eye, a flicker of curiosity passing through her violet pupils.

This man… he was like a mist, thick and elusive.

How many more secrets was he hiding?

Ron turned his gaze back to Tanjiro and grinned.

"You asked earlier how I knew about you. Well, you and I actually share a bit of a connection."

Tanjiro blinked in confusion.

"...Huh?"

Ron pointed at the Hanafuda earrings dangling from Tanjiro's ear and said with a smile,

"Besides those earrings, Yoriichi shared something even more precious with your ancestor — something that's been quietly passed down through the Kamado family for generations."

"Something else…?"

Tanjiro leaned forward, hanging onto every word, unconsciously swallowing hard.

Even Shinobu and Kanao, standing to the side, were peering at Ron with wide, curious eyes.

"That something," Ron continued, "is the Hinokami Kagura — the ritual dance your father once performed. But in truth, it's far more than a dance... It's the Sun Breathing Technique — the very first and most powerful breathing style, created by Yoriichi Tsugikuni himself."

The atmosphere instantly froze.

Not a sound could be heard.

"The strongest… breathing style?"

Shinobu and Kanao stared in shock.

Tanjiro's eyes went as wide as saucers.

"Sun Breathing…?!"

Ron nodded.

"That's right. Yoriichi was born with a natural understanding of the Breathing Techniques—an instinct that no one else possessed. From a young age, he wielded a style that would later be named Sun Breathing—the first and most powerful of them all.

But when he tried to pass it on, no one could keep up. The sheer precision, physical strain, and intensity were too much for the others. So instead, he helped his students develop alternate styles—Water, Flame, Thunder, Wind, and Stone—each one tailored to match their strengths."

He paused for a moment, the firelight flickering in his eyes.

"You could say Sun Breathing is the origin of every breathing style that exists. It embodies the entire system. Like the sun itself, it burns with overwhelming strength—its techniques are devastatingly effective against demons. Without a doubt, it's the strongest Breathing Style in existence."

The three of them were utterly stunned, too shaken to speak.

Tanjiro stammered,

"B-But… I-I've never learned anything like the Sun Breathing Technique…! My father was just an ordinary…"

His words faltered.

He suddenly froze.

Was his father… really just an ordinary man?

"To prevent the Sun Breathing Technique from vanishing forever, Yoriichi disguised it," Ron explained gently.

"He wove it into the Kamado family's ceremonial dance. Hidden right there, in plain sight, it's been secretly passed down through your family."

Ron smiled warmly at Tanjiro.

"The Hinokami Kagura… that's the Sun Breathing Technique."

At those words, Tanjiro's mind went completely blank.

Of course he remembered the Hinokami Kagura.

He could still see it clearly: his frail father dancing tirelessly in the heavy snow under the starlit sky, moving with a grace that defied his fragile body.

Butterfly Shinobu watched Tanjiro's expression, and from the look on his face, she knew:

Ron wasn't lying.

Everything he said was true.

Ron gently placed the sleeping Nezuko down onto the soft grass, then picked up a fallen branch nearby. Standing up, he looked at Tanjiro—who was still lost in a daze of shock—and chuckled lightly:

"I said we are connected by fate, didn't I? It's because... we are both users of the Sun Breathing."

"Those who walk the same path... are destined to meet."

"Since I have arrived in this world, consider it my way of repaying the bond forged through the Sun Breathing. Tanjiro, I will make you stronger—strong enough to rival Yoriichi Tsugikuni himself, the man once blessed by the gods. You will inherit the will he could not fulfill, the will of the one who, despite everything, failed to slay Muzan Kibutsuji... You will be the one to end this thousand-year-long curse."

At that moment, Ron stood there casually clutching a dried branch with his hand.

Yet in Tanjiro's eyes, he wasn't just a man standing there—he was like a towering, mist-shrouded mountain whose peak could not even be seen.

An overwhelming aura radiated from him, so heavy that even Shinobu felt her breath catch in her throat.

Ron lowered his gaze to Tanjiro and pointed the dried branch straight at the Nichirin Blade lying by Tanjiro's side.

"Come."

Under that crushing pressure, Tanjiro stared into those serene yet commanding blue eyes and felt his heart quake violently.

A fear he had never known before surged through him—so cold and bone-deep it was as though he had fallen into an icy abyss.

The fear of death.

The fire crackled quietly.

The forest around them seemed to fall into an eerie silence.

"What's wrong? Hurry up and grab your sword. Weren't you the one who said you wanted to become stronger?"

Ron spoke again, his voice still calm but carrying an almost suffocating force.

Tanjiro swallowed hard, forcing down the paralyzing fear inside him. His trembling hand reached out for the Nichirin Blade lying next to him.

His fingers were shaking uncontrollably.

"Huh...? Am I... really this scared?"

Tanjiro noticed his own fear and couldn't help feeling confused. He had fought ferocious demons at the brink of death before—he had stared death in the face countless times—yet never once had he been gripped by fear like this. Why now?

He clutched the Nichirin Blade tightly and slowly pushed himself up, standing before Ron—the unfathomable man clad in black.

So this is it...

I understand now...

Tanjiro tightened his grip around the sword's hilt.

Demons were terrifying, yes, but if he gave it his all, he could still find a sliver of hope for victory.

But now...

Sweat streamed down his forehead as he clenched his sword with both hands, locking eyes with Ron's serene, downward-looking gaze.

Standing before him now wasn't a man he could defeat—not even in his wildest dreams.

He was a monster.

Ron casually raised the dried branch in his right hand, beckoning,

"Come. Attack me with everything you've got."

Feeling the vast gulf between their strengths, Tanjiro didn't hesitate for even a second.

He stomped the ground and charged forward, the black blade of his Nichirin sword slashing in a swift, straight arc toward Ron.

Water Breathing, First Form: Water Surface Slash!

A ripple of blue water seemed to follow the blade's motion, surging toward Ron.

But—

"Too slow."

Ron spoke softly.

With just a slight shift of his body, he easily avoided the strike. His dried branch flickered like a blur of gray light, stabbing mercilessly at Tanjiro's throat.

"So—so fast!!"

Every hair on Tanjiro's body stood on end.

He desperately leaned back, narrowly avoiding the fatal strike—but even so, a shallow cut opened up across his neck, blood seeping out.

Ron looked down calmly at Tanjiro, who had fallen backward onto the ground, and lightly lifted the brittle branch that looked as though it might snap at any moment.

"Focus."

"Don't think about which technique to use, or when to swing your sword. Leave everything to your body. Fight purely on instinct. If you can't... you might actually die."

Tanjiro stared up at him, pupils shrinking in fear.

He could smell it.

That wasn't a bluff.

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T/N:

New Novel published!

Middle-Earth: Kaen, Lord of Light

If you're interested in The Hobbit or Lord of the Rings, you might like it.