The rotting leaves and mud beneath her feet felt as though they were soaked in blood—sticky and slick.
The thick demonic aura in the air was so dense it made her dizzy, stealing her sense of direction.
Mukago had been running through this mountain for three or four days now.
Suddenly, a scent that made her uneasy drifted over. She slammed to a halt.
Looking up, she saw several strands of pale white spider silk—so faint they nearly blended into the heavy mist—descending silently from above.
Though they looked light and fragile, Mukago knew full well that if she were caught in them, her flesh would be torn open without mercy.
"Tch..."
She spat irritably and clumsily leapt backward, narrowly avoiding the descending threads.
These past few days, she had been like a lost moth, circling endlessly within this mountain where the fog never dispersed, struggling to evade the omnipresent [spider webs].
It had all started with her own curiosity.
A few days ago, in the countryside of Fukushima, she had run into the bedraggled Rokuro.
Seeing that uncle—who always carried himself with the air of an adult—reduced to something like a stray dog stirred a faint sense of schadenfreude in her heart.
As for his warning, it had sounded more like the ramblings of an old man relapsing into some chronic ailment. Was he trying to bully her for being newer to the ranks? Or hiding something good for himself?
Please. They were all demons less than a hundred years old. What was he pretending to be— onmyōji?
On top of that, Rokuro had specifically mentioned that this Lower Five was favored by Master Muzan, which left a sour taste in her mouth.
"So what if he's Lower Five? I'm Lower Four!"
And so she had come.
But her breezy arrogance was quickly shattered by a little boy dressed in a white kimono with strange white hair.
"Are you... lost?"
He had appeared abruptly in midair amid the swirling mist, sitting atop a thick spider thread, lightly swinging his legs.
A ghastly pale face. Hollow, vacant eyes. Bloodless lips.
Mukago had to admit that the moment the boy appeared, she felt immense pressure.
Compared to Rokuro, the aura emanating from this one was far more powerful.
Who was he?
"I'm asking—did you come here because you're lost, Lower Rank demon?" he repeated, his voice carrying the innocence of a child, though the tone sent chills down her spine.
Mukago froze for a moment. Though unease gnawed at her, she lifted her chin, striving to maintain the dignity of a Demon Moon.
"W-What nonsense! I'm Lower Rank Four! How could I possibly be lost?"
"I... I was just wandering around. I won't disturb you..."
She tried to slip out of his line of sight, only to be blocked by a net of interwoven spider threads.
"Lower Rank Four... Are you strong?"
The boy brushed aside the bangs of his long hair, revealing turquoise eyes like glass marbles.
[Lower · Five]
As expected. He was one of the Lower Demon Moons—Rui.
Under his icy gaze, Mukago forced herself to speak. "Of course! I... I'm far stronger than a brat like you!"
Rui nodded, speaking in a light, cheerful tone. "That's wonderful... Would you like to become my family?"
"Father protects Mother. Mother protects the children. Big sister protects little brother... Since you're strong, you can be my big sister."
Eh? Family? Big sister?
The last time Mukago had heard that word was decades ago, when she had still been the daughter of a wealthy family.
But those foolish people had never been worthy of being her family. Only a man as powerful and beautiful as Master Muzan was worthy of being Mukago's family.
Still... what did this brat mean? Did he want to be friends? Or something else?
He did seem rather strong. And if he was favored by Master Muzan... perhaps growing closer to him would bring her some benefits too?
At the very least, Mukago wanted to know why he was valued.
"Sure," she hesitated briefly before agreeing. "Two Demon Moons becoming family doesn't sound so bad, right?"
For a fleeting moment, Rui's hollow eyes seemed to brighten—then the light vanished.
"That's great..." He leapt lightly down from the thread, landing before her. "Then let's play a game, big sister..."
"A game?" Mukago blinked.
"Mm. Hide-and-seek." Rui nodded, an unsettling anticipation surfacing on his pale face. "You hide, and I'll find you. If I catch you..."
He tugged lightly on the spider thread in his hand. The ominous aura it emitted made Mukago shiver.
"...I'll peel off your face and make you just like me, big sister."
Mukago's heart skipped violently. Perhaps she had truly wronged Rokuro...
But before she could think further or refuse, Rui's figure blurred strangely, like mist blown apart by the wind. Only his soft voice lingered among the trees.
"The game has begun, big sister. Hide well..."
From that moment on, the nightmare began.
At first, Mukago had carried a trace of disdain. How difficult could a child's game be?
She activated her Blood Demon Art, causing vines to sprout beneath her feet and carry her swiftly through the forest, attempting to leave this area.
Her ability allowed her to manipulate and invigorate plants, releasing deadly or beneficial toxins at will. Her body was far sturdier than that of ordinary demons.
Yet no matter how fast she ran, no matter which direction she chose, the forest had already transformed into a vast, endlessly looping corridor. No matter how she struggled, she could not escape.
The spiderweb traps were everywhere and incredibly sharp. Even the slightest touch would slice open the skin of a Demon Moon like her.
Relying solely on a demon's physical prowess and her sensitivity to vegetation, she weaved desperately through the increasingly dense labyrinth of webs, in utter disarray.
Was this brat really Lower Five? Why was he this strong?
"Big sister... where are you?"
The childlike call drifted eerily from deep within the mist—left and right, front and back—sometimes seeming right by her ear, sometimes impossibly distant. Her back prickled with fear.
Yet whether it was heaven taking pity on her or Master Muzan watching over her, since yesterday, more and more human presences had begun appearing in the mountain.
Was it the Demon Slayer Corps? Or just ordinary hunters? Mukago didn't know, but it undeniably eased the pressure on her.
She could feel Rui's attention being divided. The encirclement of spider threads had grown less dense.
Perhaps compared to dealing with intruders, tormenting her—a fellow Demon Moon—wasn't that important.
Dodging another trap, Mukago suddenly dove headfirst into a thick cluster of bushes, narrowly escaping Rui's now half-hearted search.
Had she survived this round? The tension in her nerves loosened slightly.
No. She needed to leave quickly. This place was truly cursed...
...Fate seemed determined to toy with her.
Before she could even find a direction to escape, a sharp presence sliced through the vegetation within her perception and came straight for her.
Eh?
She turned her head—only to see a flash of emerald blade light before her eyes.
Shhk!
Mukago dodged with all her strength. The tip of the blade grazed her cheek, carving a wound deep into the flesh.
Dark red blood gushed out. Terrified out of her wits, Mukago scrambled upright on hands and feet, staring at the one who had swung the blade.
The colorless sword gleamed beneath the moonlight. The man holding it locked his gaze onto her body as if staring at a corpse.
"You dodged?"
He flicked the demon blood from his blade. A powerful breath surged once more through his nose and mouth.
"Breath of Wind: First Form—"