This year, the blizzards on Mount Kumotori seemed even harsher than usual.
Howling wind swept through the forest, bringing with it a biting cold that cut to the bone.
Dozens of kilometers away from the Kamado home, deep in another stretch of woodland, a man's ragged breathing echoed through the storm—urgent, animalistic.
"Hah… hah… hah…"
It was a tremor that even the heavy snowfall couldn't bury—an instinctive shudder rising from the very depths of the soul.
How long had it been since he'd felt this?
Ever since the man named Tsugikuni Yoriichi died, Kibutsuji Muzan had lain low for countless ages… and only then had he finally dared to show himself in this world again.
He was the progenitor of demons. Over the centuries, he had amassed overwhelming power and authority, with countless strong subordinates beneath him. He should have been calm, untouchable, in complete control.
And yet now…
Now he was fleeing like a kicked dog.
All because of that boy's opening stance—and those hanafuda earrings.
Akaza didn't understand why Muzan was reacting so violently, and Muzan clearly had no intention of explaining. He snapped his head up and screamed into the swirling snow, his voice audibly shaking.
"Nakime!"
Clang—!
The instant the word left his mouth, a crisp pluck of biwa strings rang out, and the blizzard was cut away as if sealed behind a wall.
The snow beneath their feet vanished in a blink, replaced by the interlocking wooden corridors of the Infinity Castle.
"Hah… hah…"
Back within this absolutely "safe" otherworld, Muzan finally seemed to regain the right to breathe.
He collapsed beside a pillar, both hands clamped over his throat and chest as if trying to hold himself together.
Four hundred years.
A full four hundred years had passed. The wounds left by that man's blade should have long since healed—yet the moment he saw that boy, he felt a scorching pain, as if he were being burned alive all over again.
Those earrings… that red hair… that opening stance…
Muzan closed his eyes, forcing his breath to steady.
His face was as white as paper. Veins bulged at his temples, twitching with the violence of his emotions, while his lips moved in a frantic whisper.
"Impossible… This is impossible…"
"That man should be dead… so why has that rotting ghost appeared again?!"
"Muzan-sama…"
At last, Akaza—who had been following closely behind—couldn't stop himself from speaking. He stared at Muzan in stunned disbelief.
Even now, he had no idea what had happened.
This was Muzan. In all his years, Akaza had never once seen this man—always elegant, always composed—reduced to something so disheveled and panicked.
What had happened inside that little cabin…?
He didn't understand. But as he watched Muzan's collapse, Akaza's warrior's instinct latched onto the core of it—the one thing that mattered.
The one who had shaken Muzan so badly… had to be that boy from the cabin.
With that thought, Akaza dropped to one knee and spoke heavily.
"Though I do not know who that boy truly is… from your words, it sounds as though the 'real threat' you fear should already be dead."
Muzan stopped cold.
His crimson slit-pupils locked onto Akaza, murderous and sharp.
Akaza lowered his head, but his tone remained firm.
"If he is dead, then he cannot return. That boy may simply have inherited some kind of technique… or he is nothing more than an imitator putting on a show."
"You are the King who rules the night. To be frightened away by a dead man's shadow would be—"
He didn't get to finish.
A horrifying pressure crashed down, making Akaza's bones creak under its weight.
But he still didn't fall silent. He raised his head, his eyes burning with fierce eagerness.
"I beg you—allow me to test him."
"Test him?"
Muzan narrowed his eyes. His gaze flickered.
"Yes. If he truly is the reincarnation of some monster, then my death is a small price."
Akaza clenched his fist, voice low.
"But if… he is only an empty shell, bluffing behind a borrowed image… then I will bring you his corpse, and soothe your wrath."
The Infinity Castle fell into a deathlike silence.
Only the lingering resonance of Nakime's biwa drifted through the distance.
Muzan stood in shadow, his plum-red eyes glinting in the dark.
The fear was still there.
It was the primal dread of prey before its natural predator.
But Akaza's words forced cold reason back into Muzan's mind.
Yes… Yoriichi was dead.
That man had already been old, a dying ember in the wind back then. Muzan had only begun moving freely again after confirming Yoriichi's death.
And that boy—how old did he look?
At most, only in his teens.
Maybe he was a descendant. Maybe it was nothing more than coincidence.
After all… if it truly were Yoriichi, then Muzan's head would have been severed in that instant.
Could it be… that I was overreacting? That the earrings frightened me?
As rationality returned, Muzan's ragged breathing slowly calmed.
He straightened his rumpled collar. His face remained pale, but the arrogance and cold cruelty of a Demon King rose back to the surface.
"You're right, Akaza."
Muzan's voice was icy again—though now laced with caution.
"That man is dead. That is fact. And that little brat… is nothing but a disgusting counterfeit."
He turned away, back to Akaza, staring at the ornate structures of the Infinity Castle for a long time in silence.
Then, at last, he spoke—issuing his order.
"I've decided. You will not go. You are an Upper Rank—too conspicuous. You would draw the attention of the Hashira."
"I will send other demons instead."
Akaza froze, then blurted out urgently, "Muzan-sama, I—"
Before he could say more, Muzan slowly turned his head.
Those crimson slit-pupils stared straight through him.
The next second, a brutal aura detonated.
"Pfft—!"
Akaza didn't even see what happened. An invisible force slammed into him, launching him backward. He crashed into a wooden pillar, blood spraying from his mouth.
"Are you instructing me on how to act, Akaza?" Muzan said coldly.
"Kh—"
Akaza forced himself up at once and knelt again. His mouth was full of blood, yet he didn't dare show the slightest resentment.
"…I would never."
Only then did Muzan look away, snorting.
"Our priority is the Blue Spider Lily. As for that boy… I will have someone probe him."
"If it doesn't go smoothly, then my suspicion is correct."
"But if he truly is just an ordinary human—if he was only bluffing back then…"
A cruel smile spread across Muzan's face.
"Then cut off his head."
…
Night was black as ink. Moonlight filtered through gaps in the branches, spilling onto the winding forest road.
The boy called "Tanjiro" carried a wooden box containing Nezuko on his back as he walked toward the Demon Slayer Corps headquarters.
Leading the group at the very front was Tomioka Giyu—the Water Hashira—walking alone. Even from behind, his silhouette looked strangely lonely.
"Oh my, Tomioka-san is as antisocial as ever."
Shinobu Kocho walked beside Yoriichi with her hands clasped behind her back, smiling as she eyed the Water Hashira's retreating figure.
"Could it be he thinks we're too slow?"
"Or perhaps… he finds it exhausting just to breathe the same air as us?"
In truth, it wasn't only Giyu—Shinobu herself also kept a certain distance from Yoriichi. Her wariness toward this mountain boy had only deepened.
Hearing her sharp little remarks, Giyu didn't seem to react at all. If anything, his pace quickened.
Once he'd pulled farther ahead, Shinobu finally withdrew her gaze.
When she looked back at the boy beside her, her tone became slightly more serious.
"Now then, Tanjiro-kun—there's something I should tell you first."
"Regarding your family, Master has already arranged another unit of the 'Kakushi.'"
"They will be taken to a highest-security Wisteria House. It's protected by the Corps' strongest barrier and thick wisteria scent—even the Twelve Kizuki won't be able to approach easily. So you can rest assured."
At the mention of his family, the boy's expression—usually so blank—softened ever so slightly.
"Thank you," Yoriichi said, sincerely.
"No need to thank me. It was Master's decision. I'm only following orders."
Then Shinobu's tone shifted again, light and casual—as if she were chatting about nothing at all.
"That said… I'm still very curious."
Her eyes fixed on him, as though she intended to peel him open and read whatever lay underneath.
"How did you know? About those 'little secrets' inside my body."
Yoriichi kept his eyes forward, as if he hadn't noticed her scrutiny—her attempt to see through him completely.
"I saw it with these eyes," he answered evenly.
"You saw it…?"
Shinobu raised her brows. Her expression was gentle, but her voice carried something deeper—something difficult to pin down.
"You mean your eyes can see through clothing? Oh dear. That sounds like a troublesome and rather vulgar ability."
If he'd been a normal teenage boy, he would probably have panicked and flushed crimson as he tried to explain.
But Yoriichi didn't.
He stopped, turned to face her, and met her gaze with those dark red eyes.
In that instant, Shinobu felt as if she were standing naked before him—like every mask, every secret, even the speed of her heartbeat was laid bare.
The air between them grew strangely still.
Just as Shinobu was about to break the silence, the boy's flat voice spoke.
"Not clothing."
He said calmly, "Flow."
"Flow…?"
Yoriichi gave a small nod.
"I saw the blood vessels inside your body. Your organs. Even within every strand of muscle fiber—wisteria poison has settled there. At that dosage, it's no longer just a 'weapon.'"
He paused, his gaze dropping to her slender wrist.
"You're using your body as a vessel. Day after day, you ingest poison—refining yourself into bait made for a specific demon."
The air froze.
Shinobu's smile locked in place.
What he described… was virtually her greatest secret. The final trump card she'd prepared to kill the Upper Rank demon who murdered her sister.
A plan of mutual destruction.
"…That's a terrifying level of insight," she murmured at last.
After a long silence, Shinobu lowered her eyes. The curve of her lips turned bitter, and her voice sank.
"If you can see that clearly, then you should understand, shouldn't you? There's no other way."
She lifted her head. Deep in her eyes, hatred and helplessness churned, barely restrained.
"I'm small. I don't have the strength. I can't even cut through a demon's neck."
"In this cruel world, if the weak want revenge—if they want to kill those immortal monsters—then the only way is to turn themselves into poison."
"This is my only value."
"And my only chance."
She forced her smile back onto her face, but now it carried a self-destructive resolve.
"So no matter how you found out… Tanjiro-kun, don't interfere with me—"
"No need."
The boy cut her off.
Shinobu blinked. "What?"
"That kind of 'chance' isn't needed."
Yoriichi continued walking. Under the moonlight, his back looked thin and fragile—yet somehow it carried a weight like an immovable mountain.
"If someone has to trade their life for victory just because they're not strong enough… that kind of logic is sorrowful."
"W-What… are you talking about?" Shinobu snapped—rare irritation rising as she hurried after him.
"You don't understand how strong an Upper Rank demon is! Even a Hashira can—"
Rustle—
A shadow burst from the brush ahead.
It was a grotesque demon that had been lurking for some time, drawn by the human presence of the Kakushi. With a roar, it launched itself at one of the rear-most members.
"Watch out!" Shinobu's eyes sharpened. She pushed off the ground, about to trigger Insect Breathing—
But her fingers had only just brushed her sword hilt.
Clack.
A crisp sound of a blade being sheathed rang out right beside her.
Shinobu froze.
She hadn't even seen when the boy drew his sword—let alone how he moved.
Ahead, the demon still hung midair… and then its body stiffened.
A hair-thin red line appeared across its neck.
There was no spray of blood. No scream.
Its head slid slowly free, and the instant its body hit the ground, it crumbled like snow touched by sunlight—turning into ash and vanishing.
That was no ordinary cut.
As someone who understood anatomy and demon physiology better than most, Shinobu realized with shock that the demon's regeneration had been completely suppressed.
That slash hadn't only severed its neck.
It was as if the very life force within its cells had been cut apart as well.
The boy stood beneath the moon, one hand resting casually on the hilt. The sword itself was simply a weapon he'd borrowed from the Kakushi not long ago.
He turned his head and looked at Shinobu, who stood rooted in place.
"Whether it's an Upper Rank…"
"…or Kibutsuji Muzan."
His calm voice carried clearly on the night wind.
"As long as I'm here, no one needs to become bait."
"Get rid of the poison in your body," he added. "It's not good for you."
Then, without giving her any time to respond, he turned and followed after the group.
Up ahead, Tomioka Giyu stopped.
He didn't turn around, but the hand gripping his hilt loosened slightly.
Just a moment ago, he'd been ready to draw—only to find the demon's presence vanish in an instant.
"…Was I too slow?" he muttered.
After a brief silence, he adjusted his breathing and continued forward.
Shinobu stared at the boy's back, unmoving for a long time.
The night wind lifted the butterfly-wing pattern of her haori. Only when his figure was about to disappear entirely did she finally snap out of it, pressing a hand to her chest.
There—her heart, once aching day and night from the poison's slow corrosion—now hammered violently for a different reason.
A tremor named hope.
"…What a strange man," she whispered.
And this time, the false smile she always wore finally vanished.
Moonlight washed over her refined, pale face. In her eyes was something faint—something human.
"Then let me see it…"
"…how much of your 'big talk' you can truly make real."
She stepped forward and followed after him.
Only this time, she walked a little closer to that back.
-------
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