Chapter 35 — The Demon Moon of Spider Mountain
The rotten leaves and mud beneath her feet felt slick and sticky, as if soaked in blood.
The air was thick with demonic aura, so heavy that it made one dizzy and robbed them of any sense of direction.
Mukago had already been wandering through this mountain for three or four days.
Suddenly, a faint scent that made her uneasy drifted through the air.
She halted abruptly.
Looking up, she saw several strands of pale white spider silk, nearly indistinguishable from the surrounding fog, silently descending from above.
They looked light and delicate.
But Mukago knew very well—
Once that stuff wrapped around you, torn flesh and shredded skin were inevitable.
"Damn…"
She clicked her tongue irritably and clumsily jumped backward, avoiding the falling threads.
Over the past few days, she had been like a lost moth, wandering aimlessly through this vast mountain where the fog never seemed to disperse, constantly dodging the invisible "insect traps" scattered everywhere.
And all of this—
Was because of her own curiosity.
A few days earlier, she had encountered Rokuro in the countryside of Fukushima.
The normally arrogant senior demon had looked utterly miserable.
Seeing that man—who always acted like some superior adult—reduced to a stray dog chased out of its home, Mukago couldn't help feeling a little amused.
As for his warning?
To her, it had sounded like nothing more than the ramblings of an old man relapsing into his usual nagging.
Maybe he just wanted to bully her because she had become a demon later than him.
Or maybe he was hiding something good.
Please.
We're all demons who haven't even lived a hundred years.
Why are you acting like an expert or something?
On top of that, Rokuro had specifically mentioned something else—
That the Lower Rank Five demon in this mountain was particularly favored by Lord Muzan.
That comment made Mukago feel slightly jealous.
"Lower Five? So what?"
"I'm Lower Rank Four!"
And so—
She came.
Unfortunately, the confidence and arrogance she had carried with her were quickly shattered.
The one who crushed them was a small boy.
He wore a white kimono and had strange long white hair.
"You… are you lost?"
He appeared suddenly in the misty air, sitting atop a thick strand of spider silk and gently swinging his legs.
His face was deathly pale.
His eyes were hollow and lifeless.
His lips carried no trace of blood.
Mukago had to admit—
The moment the boy appeared, she felt a tremendous pressure.
Compared to Rokuro, the aura surrounding this boy was far stronger.
Who is he?
"I asked you something," the boy said again.
"Did you come here because you got lost… Lower Rank demon?"
His voice still carried the innocent tone of a child.
But the words themselves sent a chill down one's spine.
Mukago froze for a moment.
Though uneasy, she still lifted her chin, forcing herself to maintain the dignity of a Demon Moon.
"W-What nonsense!"
"I'm Lower Rank Four!"
"How could I possibly get lost?"
"I was just wandering around… I'll leave you alone."
She tried to slip out of the boy's line of sight.
But before she could move far, countless spider threads suddenly stretched out, forming a web that blocked her path.
"Lower Rank Four…"
"Are you… strong?"
The boy brushed aside the long bangs covering his forehead.
Beneath them were glass-like turquoise eyes.
Inside the pupils was a clear marking:
Lower • Five
Just as she thought.
A member of the Lower Moons.
Rui.
Under his cold gaze, Mukago felt her confidence falter slightly.
Still, she forced herself to speak.
"Of course!"
"I'm… I'm much stronger than a little brat like you!"
Rui nodded calmly.
His voice sounded almost cheerful.
"That's wonderful."
"Then… would you like to become my family?"
"Father protects Mother. Mother protects the children."
"The older sister protects the younger brother…"
He tilted his head slightly.
"Since you're strong, why don't you become my older sister?"
"Huh?"
Family?
Older sister?
The last time Mukago had heard that word had been decades ago—
Back when she was still the daughter of a wealthy household.
But those foolish people had never been worthy of being her family.
Only someone as powerful and beautiful as Lord Muzan was worthy of that role in Mukago's eyes.
Still…
What exactly did this brat mean?
Was he trying to make friends with her?
Or something else entirely?
He really did seem quite powerful.
And besides… if he was truly favored by Lord Muzan, then getting closer to him might bring some benefits.
At the very least, Mukago wanted to know why he had earned Muzan's attention.
"Alright," she said after a moment of hesitation.
"Two Demon Moons becoming family… doesn't sound so bad."
For an instant, the emptiness in Rui's eyes seemed to brighten.
But the glimmer vanished just as quickly.
"That's wonderful…"
He leapt lightly down from the spider silk and landed in front of her.
"Then let's play a game, Sister."
"A game?" Mukago blinked.
"Yes. Hide-and-seek."
Rui nodded. On his pale face appeared an eager expression that sent chills down her spine.
"You hide. I'll look for you."
"And if I catch you…"
He tugged lightly on the spider thread in his hand.
The ominous aura emanating from it made Mukago shiver.
"…I'll peel off your face and make you look just like me, Sister."
Mukago's heart skipped violently.
Maybe… Rokuro-senpai wasn't exaggerating after all…
But before she could think further—or refuse—
Rui's figure blurred strangely, like mist scattered by the wind.
Only his soft voice lingered in the forest.
"The game has begun, Sister."
"Make sure you hide well…"
From that moment on—
The nightmare began.
At first, Mukago still held a trace of contempt.
How difficult could a child's game possibly be?
Activating her Blood Demon Art, vines sprouted beneath her feet, carrying her swiftly through the forest as she tried to flee the area.
Her ability allowed her to control and animate plant life, releasing toxins that could either harm enemies or strengthen herself.
Her body was also far stronger than that of an ordinary demon.
And yet—
No matter how fast she ran…
No matter which direction she chose…
The forest had become a massive looping corridor.
No matter what she did, she could not escape.
The spider-web traps scattered everywhere were terrifyingly sharp.
Even the slightest touch would slice open the skin of a Lower Moon demon like her.
She could only rely on her demonic reflexes and her sensitivity to plant life, desperately dodging through the increasingly dense labyrinth of webs.
Her escape was miserable and frantic.
Is that kid really Lower Five?
Why is he this strong?
"Sister… where are you?"
The innocent call of a child echoed faintly from deep within the mist.
Left, then right.
Ahead, then behind.
It sounded both close to her ear and impossibly distant.
Mukago felt the hairs on her back stand up.
But perhaps fate—or perhaps Lord Muzan's blessing—had not completely abandoned her.
Since yesterday, many human presences had begun appearing in the mountain.
Were they Demon Slayers?
Or just ordinary hunters entering the forest?
Mukago didn't know.
But their presence undeniably eased the pressure on her.
She could sense Rui's attention being divided.
The spider-web traps no longer closed in as relentlessly as before.
Perhaps compared to dealing with intruders, tormenting a fellow Demon Moon simply wasn't worth the effort.
Dodging another web trap, Mukago suddenly dove into a dense thicket.
She managed to evade Rui's now less-focused search.
Did I escape…?
The tension in her nerves loosened slightly.
No. I need to leave this place as soon as possible.
This mountain is seriously cursed…
But fate seemed determined to mock her.
Before she could even choose a direction to flee—
A sharp presence sliced through the plants within her perception and came straight toward her.
"Huh?"
She turned her head—
Just in time to see a flash of emerald-green blade light.
Shing—!!
Mukago twisted desperately to evade it.
The tip of the blade grazed past her cheek, carving a deep wound into her flesh.
Bright crimson blood spilled out.
Terrified out of her wits, Mukago scrambled backward and looked up at the attacker.
The colorless blade gleamed under the moonlight.
The man holding it stared at her with cold eyes—
As if he were looking at something already dead.
"You dodged that?"
He flicked the demon blood from his blade.
His breathing grew steady and powerful once more.
"Wind Breathing — First Form…"