The forest stood silent under the heavy weight of winter, branches sagging with snow as two figures pressed onward. Tanjiro's breaths came out in puffs of steam, his arms tightly wrapped around Nezuko—his sister, his last family. Her body rested in a woven basket strapped to his back, hidden from the pale morning sun beneath thick layers of cloth.
The events of the previous day clung to him like frostbite—cold, numbing, inescapable.
She was no longer human. But she wasn't a monster either.
Before departing, Giyu Tomioka, the strange man with the blue-patterned haori and unreadable eyes, had left behind words etched with steel:
"Your sister is a demon. But she protected you. That's not normal."
Tanjiro clung to that hope like a lifeline.
"She cannot be exposed to sunlight," Giyu warned. "Ever. The sun will burn her to ash. And to avoid provoking others, muzzle her. If you lose control of her—even once—I will be the one to end her."
His hands had been steady when he said it. Unemotional. But not cruel.
And so, Nezuko now bore a bamboo muzzle—securely tied across her mouth, silent proof of her inner war.
Tanjiro's journey began with quiet desperation. Climbing steep trails, searching for an unfamiliar name: Sakonji Urokodaki. A man who might teach him how to fight, how to protect what remained. His only clue was that Urokodaki lived at the foot of Mount Sagiri.
Night fell fast.
He found a temple—and blood.
The stench struck him like a storm.
Inside, bodies lay sprawled, lifeless and still warm. A grotesque figure crouched over them, its eyes glowing yellow, claws dripping red. Another demon.
Tanjiro's fear returned—but he had no choice.
He attacked with a hatchet, using his surroundings as weapons. The demon was strong—inhumanly fast, almost laughing as it fought. But Tanjiro was resourceful. He used his momentum to pin it, the blade lodged deep into its body.
Then Nezuko appeared.
The demon lunged for her—but she grew in size, feral in form, and with a swift kick, sent its head flying across the floor.
For a moment, it seemed dead.
But the body kept moving.
Headless—and still dangerous.
Tanjiro froze.
He gripped his blade and placed a foot on the demon's chest. He raised the axe. His heart pounded. This was the moment to kill. To finish it.
But he hesitated.
His fingers trembled.
The demon cried out, not in pain—but in mockery.
From the trees above, a red mask watched.
The figure descended—masked, robed in mountain colors, silent as mist. In a breath, he bound the demon and stood beside Tanjiro, unmoving.
"So you're the boy Giyu spoke of," he said at last, his voice muffled and calm. "You hesitate. That hesitation will cost lives."
Tanjiro could only stare.
The masked man lifted the demon and vanished into the night with the speed of a ghost.
By dawn, Tanjiro stood at the base of Mount Sagiri, Nezuko asleep inside her basket. The climb ahead was steep and covered in mist.
The mountain would not welcome him.
But neither would the world below.
He took his first step upward, into the fog, carrying hope on his back and guilt in his chest.