Winter always came earlier to the Eternal Paradise Faith than anywhere else.
After severing a swordsman's blade at the Sacred Canon and extorting half of a wealthy merchant's fortune, Inosuke's days had grown increasingly comfortable.
Steward Sato obeyed his every word, and even the high-ranking believers—who normally looked down on everyone—had to bow respectfully and call him Young Master whenever they saw him.
But Inosuke didn't indulge too deeply in this hollow vanity. He knew very well that all of these privileges were built atop Doma's whims.
Still… the pride of a Young Master inevitably took root in his heart.
Seven-year-old Inosuke was dressed in an elegant blue-patterned kimono, a Nichirin Blade at his waist, casually tossing several heavy gold plates in his hand as he swaggered through the snowy streets of the mountain town below.
"Young Master, please slow down. Be careful not to slip,"
Behind him, Sato followed with two attendants, arms full of packages, panting heavily.
"Shut up. You're too slow."
Inosuke didn't even look back. His wooden clogs crunched lightly atop the snow.
Thanks to his Agility Enhancement, he moved across the snow as if on flat ground, fast enough that the adults behind him could barely keep up.
And with his Ice Spirit Physique, he wore far thinner clothes than most, feeling no cold at all—rather, he enjoyed the biting winter wind.
There was only one purpose for coming down the mountain today.
Spending money.
The cult had everything—but certain special items could only be found in human marketplaces.
"Waaaaaah!
I don't want to go! I don't want to!
It's too far! I'll die! I'll definitely die on the road!"
Suddenly, a shrill wail pierced through the bustle of the marketplace.
Inosuke frowned.
The crying was high-pitched, desperate, on the verge of collapse—yet surprisingly full of breath.
"So noisy."
He stopped and glanced toward the far end of the street.
There, a filthy little boy wearing a yellow haori was clinging desperately to a utility pole, his face smeared with snot and tears.
No matter how a man who looked like a loan shark tried to yank him away, he refused to let go.
"Grandpa! Help!
I'm going to be sold off!
I don't want to work hard anymore—I want to go home!"
Messy black hair, and a face that—even distorted by tears—still showed unmistakable cowardice.
Agatsuma Zenitsu.
The future Thunder Hashira… or perhaps the future noise-making machine.
Inosuke narrowed his eyes.
Zenitsu looked about six or seven now—probably just scammed out of his money. Pitiful, and a bit ridiculous.
"Young Master, that beggar is too loud. Should I have him chased away?"
Sato asked eagerly as he stepped forward.
"No need."
Inosuke withdrew his gaze, a faintly amused smile curling his lips.
Zenitsu was still useless at this stage. Interacting with him brought no benefit—only trouble.
"Let him cry.
Anyone who can cry that loudly has decent lung capacity. He's got the makings of a martial artist."
He tossed off the comment casually, then turned and walked into a nearby blacksmith's shop.
Sato stood there blankly, scratching his head. Makings of a martial artist? That crying little brat?
The Young Master's perspective was becoming harder and harder to understand.
...
The blacksmith was meticulous.
By the time Inosuke emerged, the sky had grown overcast, snowflakes landing on the tip of his nose.
He was in a good mood.
Just as he was about to head back, a strange sensation brushed against his awareness.
For someone with hyper-sensitive touch like Inosuke, it felt like—
Warm. Dry. Like burning charcoal on a winter's day.
In this town steeped in desire, that aura was so pure it felt out of place.
Inosuke instinctively followed the sensation with his gaze.
At the end of the street, a boy wearing a black-and-green checkered haori crouched by the roadside, a large basket of charcoal on his back.
He was calling out to sell his wares.
His face was red from the cold, a dark scar on his forehead, and a pair of Hanafuda earrings hung from his ears.
Kamado Tanjiro.
He looked seven or eight at most, earnestly trying to sell charcoal to passersby.
His voice wasn't loud—but it carried sincerity.
"Sir, please buy some charcoal. The snow's getting heavier. If you don't have enough firewood, the night will be very cold."
Inosuke stood among the crowd, silently watching him.
A peculiar sense of fate stirred within his chest.
One—Doma's adopted son.
One—the future swordsman of the Demon Slayer Corps.
One—ice.
One—fire.
Just then, Tanjiro seemed to sense something.
That legendary nose twitched slightly.
He suddenly turned his head, gaze piercing through the crowd—locking precisely onto Inosuke.
Their eyes met.
Tanjiro froze.
From this boy—prettier than most girls—he smelled a contradiction.
The crisp clarity of eternal snow…
and beneath it, an unfathomably deep stench of blood.
He had never smelled anything like it.
But this boy… was still so young.
Inosuke felt a faint sting across his skin as Tanjiro stared at him.
He's looking at me.
That gaze—it felt as if it could see straight through his soul.
"Young Master?"
Sato called out, confused when Inosuke stopped.
Inosuke ignored him and walked straight toward Tanjiro.
Tanjiro instinctively tensed. He didn't know why—but he felt this boy his age was dangerous.
"Hey. Charcoal seller."
Inosuke stopped in front of him, looking down from above.
He deliberately activated his lung capacity enhancement, making his voice heavy with pressure—eerily similar to Doma's.
"How much for your charcoal?"
Tanjiro blinked, then hurriedly stood and bowed.
"Um—two hundred mon for a basket. If you only need a little—"
"Too little."
Inosuke cut him off, pulling out a gleaming gold koban and tossing it over.
The gold arced through the air and landed squarely in Tanjiro's frostbitten hands.
"I'll take the whole basket."
His tone was flat.
"W–What?!"
Tanjiro stared at the gold plate, so startled he nearly dropped the basket.
"T–That's too much! I can't make change! One gold koban could buy a whole year's worth of charcoal!"
"Then keep it."
Inosuke waved impatiently.
"The rest is a tip.
What—are you looking down on my money?"
"N–No! That's not what I meant!"
Tanjiro waved his hands frantically, panic written all over his honest face.
"But my mother said you shouldn't accept payment without—"
"Tsk."
Inosuke frowned.
Won't even take free money?
He suddenly leaned closer.
The distance between them shrank to mere inches.
Inosuke clearly heard the heartbeat within Tanjiro's chest.
Thump. Thump. Thump.
Steady. Strong. Comforting.
Completely different from Muzan's chaotic seven hearts—and nothing like Doma's deathly stillness.
"Take it,"
Inosuke said quietly, his voice low enough that only the two of them could hear.
"This money isn't free.
Consider it buying a promise from you."
Tanjiro froze, staring at the impossibly beautiful boy before him.
"What promise?"
Inosuke looked at him deeply, his gaze settling on the Hanafuda earrings.
"When it gets dark, don't linger outside."
"Especially… when you smell blood like the kind on me."
With that, Inosuke gave him no chance to refuse.
He turned and waved at Sato.
"Take the charcoal.
Father's room is too cold—let's warm it up for him."
Sato stared, dumbfounded.
The Cult Leader hates heat. Aren't you asking to be scolded?
But he didn't dare disobey, only trudging off miserably to carry the charcoal.
Inosuke turned and left, his figure quickly swallowed by wind and snow.
Tanjiro stood there in the snow, holding his now-empty basket, gripping the gold koban still warm with Inosuke's body heat.
He stared in the direction the boy had vanished, sniffing lightly.
"…What a sad scent."
Tanjiro murmured softly.
"He was so domineering… yet why does he smell like…
…like he's been carrying something all alone for a very long time…"
[The main story begins]