The morning after Rui left.
Strange scraping sounds echoed through a side courtyard of the Eternal Paradise Faith.
Inosuke sat cross-legged beneath the corridor, half a jin of spider silk spread across his lap—the loot he'd extorted from Rui.
The silk truly lived up to Rui's words: astonishingly tough, impervious to water and fire, so resilient that even ordinary blades struggled to cut it. The only caveat was that Inosuke had to keep releasing cold aura into it—once exposed to sunlight without that chill, it would snap.
"Good stuff,"
Inosuke muttered, winding the translucent threads around the handle of his serrated blade, layer by layer.
The original sharkskin wrap had been non-slip, but during heavy swings it still didn't cling enough. Rui's silk, however, had a peculiar tackiness combined with elasticity. Once wrapped, the grip jumped up an entire tier.
Even with hands slick with blood and sweat, the blade would feel as if it were glued to his palm—never slipping free.
"Inosuke, what are you doing?"
Like a ghost, Doma dropped down from the ceiling upside-down, his exquisite face hanging right in front of Inosuke's. Long hair spilled downward, brushing Inosuke's nose.
"Wrapping the handle."
Inosuke didn't even look up. He tied a firm knot with practiced ease and swung the serrated blade once.
Whoom! Whoom!
The wind-splitting sound was deep and solid. Still, he frowned and lowered the blade again.
"What's wrong? Not feeling right?" Doma flipped down to the floor, gently fanning himself with his golden fan.
"Too light."
Inosuke stood, rolling his shoulders. As he grew older and continued day after day of lung-capacity training, his strength had increased at a frankly unreasonable rate.
One-handed wielding was agile, but his other hand felt empty—his center of gravity never quite reaching perfect balance. Half his body felt wasted, unused.
"And with only one blade, cutting just isn't satisfying."
He made a crossing motion with his hands.
"If two blades saw down together, meshing like a crocodile's teeth, that instant of tearing someone apart would multiply."
Doma's eyes lit up.
"Dual wielding? Oh my, that's very difficult to master.
But if it's you, Inosuke… you might even create an entirely new style."
"And this," Inosuke added, pointing at Doma's fan, then at the pair of practice fans at his own waist.
"The fans can't go either. They're not as fun for killing as blades, but for creating wind pressure, obscuring an enemy's vision, or sending your ice mist back at them—they're incredibly useful."
"So…" Inosuke lifted his head, revealing emerald eyes brimming with greed and ambition,
"Dad, I want another blade.
And I want a real pair of fans too—ones that can actually fight, like yours.
"Not those gold-plated toys that shatter on contact. I want the kind that can kill."
Doma blinked, then covered his mouth and laughed, shoulders trembling.
"Greedy. Truly greedy. Two blades and fans—are you trying to arm yourself like a hedgehog?"
He reached out indulgently and pinched Inosuke's cheek.
"As for proper fans, Daddy happens to have a pair forged from polar cold iron in the treasury. A craftsman made them two hundred years ago to curry my favor.
They're as hard as Nichirin blades—I'll give them to you as your seventh birthday present."
"And the second blade…"
Doma's gaze slid toward the cult's front gate, the smile on his lips turning faintly cruel.
"Well, how convenient. Someone's delivering one to you today. Go take it yourself."
...
Eternal Paradise Faith, Front Mountain Gate
Amid howling wind and snow, a man trudged forward in a straw rain cape, sword at his waist.
His name was Murata, a Demon Slayer Corps swordsman of the Kanoe rank. Not particularly high-ranked, but cautious, stubbornly hard to kill, and inexplicably lucky.
He'd received a Kasugai Crow's order—several young women had gone missing in this area, suspected to be linked to a cult called the Eternal Paradise Faith. He was to investigate.
"This place… the cold feels wrong,"
Murata muttered, tightening his uniform. He exhaled a white breath, his hand never leaving his hilt. The closer he drew to the grand temple, the stronger his unease grew.
Just as he stepped onto the final stone stair, a white figure abruptly appeared atop the torii gate.
A boy—only seven or eight at most—stood there. He wore luxurious blue-and-white brocade, his face bearing a noble air far beyond his years.
Most striking was his gear: on his left hip hung a tachi in a battered scabbard; on his right, two iron fans gleaming with a faint cyan light.
"Hey, you in black."
The boy looked down at Murata from above, voice clear yet carrying an unquestionable arrogance.
"This is private property. If you're carrying weapons and want to enter, leave your sword."
Murata froze, then frowned.
"Little brother, I'm just a traveler passing by. This sword is for self-defense—I can't part with it. Please step aside."
"Self-defense?"
Standing on the torii, Inosuke fully opened his innate heightened tactile sense.
In the wind and snow, he could clearly feel the aura coming off this man. Not strong—if anything, a bit weak.
But the blade at his waist…
Inosuke's gaze locked onto Murata's Nichirin sword. Indigo-blue, calm in hue, faintly gleaming with cold light.
A good blade.
Much better than the junk Doma gave me.
"I like it." Inosuke grinned, flashing sharp little tiger teeth.
"I've taken a liking to your sword. As a trade, I won't break your legs—just throw you down the mountain."
"What—?!"
Before Murata could react, the boy leapt from the torii like a snake-hunting hawk.
No words. Straight to violence.
Midair, Inosuke yanked free the spider-silk-wrapped serrated blade with his right hand, while his left smoothly drew a cyan iron fan.
Ice Breathing, First Form — Windmill Fan · Modified!
The fan swung—not to strike Murata directly, but to use Agility Enhancement to generate a bizarre vortex in midair.
Snow from the ground was swept up instantly, forming a white curtain that swallowed Murata's vision.
"Blood Demon Art?!" Murata cried in alarm, instinctively drawing his blade to slash at the snow curtain.
But the instant he swung—
A far more vicious, feral cutting sound tore through the snow.
That was Inosuke's serrated blade.
CLANG!
A thunderous crash. Murata's wrist shook violently, his palm going numb. To his horror, his Nichirin blade was jammed fast by the notched teeth of Inosuke's broken sword.
"Got you!"
Inosuke's face burst through the snow, inches away. Using the serrations to lock Murata's blade, he unleashed his core strength and twisted his waist.
"DROP IT!"
A monstrous force tore through Murata's grip. He couldn't hold on—the Nichirin blade flew free, embedding itself in the snow nearby.
The fight ended faster than expected.
In a single exchange, the Demon Slayer had been disarmed.
Inosuke didn't press the attack. Like a squirrel spotting a pinecone, he dashed over and yanked the indigo-blue Nichirin blade from the snow.
"Great blade! Really great! Hehehe!"
He swung it twice, utterly delighted. The balance was perfect, the feel smooth—clearly ideal for dual wielding.
Murata slumped on the ground, staring as the boy danced around with his sword, mind blank.
What kind of monster is this?
That snow-whirling fan technique, that absurd strength—was this really human?
"Hey!"
Inosuke suddenly turned back to Murata. New blade in his left hand, old serrated blade in his right, he frowned.
"It's asymmetrical. One's smooth, one's serrated. The feel's different when I cut."
Under Murata's horrified gaze, Inosuke carried the pristine, treasured Nichirin blade over to a large bluestone.
"What are you doing?! That's a Nichirin sword! It's precious!" Murata shouted.
"I know."
Inosuke raised the blade and smiled at the stone—a smile with an indescribable meaning.
"That's exactly why I'm turning it into something I like."
Clang! Clang! Clang! Clang!
Crisp metallic impacts rang out at the mountain gate. Sparks flew.
Every strike felt like it was smashing into Murata's chest.
He watched helplessly as his lovingly maintained blade—once clear as autumn water—was brutally ruined, jagged notches bursting along the edge until it became identical to the other blade.
A serrated sword.
"Hah…"
Satisfied, Inosuke blew the stone dust from the blade and crossed the two serrated swords before him.
Teeth interlocked, cold light flashing.
"That's better."
He sheathed one blade at his left hip, the other at his lower back, then tucked the pair of cyan iron fans into the front of his robes.
Dual blades for offense. Iron fans for defense.
Perfect in both form and function.
This was the presence befitting the Young Master of the Eternal Paradise Faith.
Inosuke walked up to the stunned Murata and looked down at him.
"Your sword is mine now."
He pulled a gold koban from his robes and tossed it onto Murata.
"That's payment. And tell the Demon Slayer Corps this area's under my protection.
"If you want to investigate, send a real Hashira. If you send lucky trash like you again, I'll rob every last one of you."
With that, Inosuke turned and sprinted back up the mountain.
"Dad! Look! I've got them all! I can use dual blades now!"
The boy's voice vanished into the wind and snow.
Murata clutched the still-warm gold koban, staring at the empty scabbard stuck in the snow, on the verge of tears.
What was this supposed to be?
Mission failed before it even started?
Or getting robbed by a seven-year-old?
"Damn it… too unlucky…"
...
Rear Hall
Doma looked over his son's new loadout and nodded in satisfaction.
"Very nice. Truly very nice."
He picked up the utterly mutilated indigo Nichirin blade, fingers brushing over the serrations.
"Though you destroyed its original structure, you've given it new life.
"Inosuke, you're quite the little artist~."
"Obviously." Inosuke smugly twirled the iron fans.
They were far heavier than the previous replicas. The ribs were sharp as blades, their edges lined with fine backward barbs. Combined with his Ice Spirit Physique, every swing carried a chilling effect.
"Dad, I should name these fans too."
Snap!
He opened one fan to hide half his face, leaving only cunning eyes visible.
"How about Devour Clouds and Exhale Mist?"
"Your taste is a bit tacky," Doma replied mercilessly.
"But if you like them, then so be it."
Doma walked to the window, watching the snowfall thicken.
"Weapons are ready. Your techniques have taken shape. Inosuke—over the next few years, you only need to do one thing."
He turned back, seven-colored eyes suddenly grave.
"Turn this mismatched combat style into pure instinct."
"Because, according to Lord Muzan's intelligence…"
Doma's voice dropped.
"The head of the Demon Slayer Corps seems to have noticed something. It may not be long before a true Hashira comes knocking."
Inosuke tightened his grip on the twin blades. The spider silk at the handles pressed firm and sticky against his palms.
"Let them come."
"Perfect timing—I need a whetstone."
Seven-year-old Inosuke stood within the palace of ice lotuses.
Fan in his left hand. Blade in his right.