Five Years Ago
The night smelled of blood.
Flames flickered across what was once a home.
Two small figures huddled together in the corner—trembling, broken.
"Onee-san… I'm scared…"
A tiny voice cracked in the darkness.
Kanae, barely holding herself together,
hugged her younger sister tightly.
"It's okay, Shinobu… I'm here…"
But her voice trembled.
Because she knew—
Nothing was okay.
A shadow loomed over them.
A demon.
Its grotesque face twisted with delight as it stepped closer.
"Such sweet little humans…"
"I wonder how you'll taste…"
Shinobu buried her face into Kanae's chest.
"Onee-san… please…"
Kanae's eyes filled with tears.
I can't protect her…
The demon raised its claw—
*Slash!
A blur passed.
The demon's claws were severed cleanly.
Silence.
A woman stood before them.
Graceful. Calm. Deadly.
Her haori shimmered like layered wings—lime green fading into Amethyst .
Her presence—soft… yet overwhelming.
The demon jumped back, its claws already regenerating.
"Grr…"
"A demon slayer… huh…"
"Yo—"
*puchi
Its voice cut off abruptly.
Blood began to stream from its eyes.
Its body trembled—
Then it dropped to its knees.
"…Poison…?"
The slayer slowly turned toward the demon.
Panic took over.
The demon tried to run toward the exit—
But—
A calm voice echoed.
"Insect Breathing…"
Her tone was gentle.
"…First Form: Silken Sting."
In a flash—
The demon's body froze mid-motion.
For a brief second—
Everything was still.
Then—
It crumbled into ash.
Kanae stared at her, eyes wide.
"Y-you…"
The woman turned toward them—
And smiled.
"It's okay now."
She knelt down and gently placed her hand on their heads.
"You're safe."
"…My name is Shizukana Hoshino."
"From today… You won't face this world alone."
Tears streamed down Kanae's face.
Shinobu clung to her.
And Shizukana… embraced them both.
-
Days turned into months.
Under her guidance—
They grew.
The sisters stood in a quiet training ground.
"Again."
Shizukana stood calmly as Kanae lunged.
"Flower Breathing: Third Form—"
"Too slow."
She vanished.
Appeared behind her.
"…Your heart wavers."
"Hold your stance properly," the woman instructed softly.
Kanae tightened her grip on the sword.
Shinobu struggled beside her.
"You're too stiff," the woman chuckled lightly.
She stepped behind Shinobu, adjusting her posture.
"Like this… feel the flow."
Shinobu blinked.
"Like… an insect?"
The woman smiled.
"Yes."
"Small… but precise."
-
Months into years.
Laughter slowly replaced silence.
Pain softened—
But never disappeared.
One evening—
Kanae approached her.
"Can I ask something?"
"Of course."
Kanae hesitated.
Then softly—
"…Can we call you… sister?"
The woman froze.
Shinobu looked up nervously.
"…Only if you're okay with it…"
For the first time—
Her composed expression cracked.
A gentle, emotional smile formed.
"…Of course."
She pulled them into a hug.
"From today… we are family."
-
1.5 Years Ago
The battlefield trembled.
Dozens of demon slayers stood ready.
Opposite them—
A legion of demons.
Shizukana stepped forward—
The battlefield… changed.
The air grew unnaturally still.
A faint hum echoed—like the fluttering of countless wings.
Behind her—
A vast, translucent aura unfolded.
Like an endless swarm.
Butterflies.
No—
Not gentle ones.
Each wing shimmered with a violet glow,
edged with something darker… something lethal.
They moved in silence.
Yet the pressure they carried—
Felt like suffocation.
Like being trapped inside a hurricane made of poison and precision.
Calm on the surface—
But inside…
Certain death.
Even the demons hesitated.
"Squad. Formation Delta."
"Yes, Hashira-sama!"
"Hold the line!"
Demons charged.
"Wind left flank!"
"Cover the rear!"
Steel clashed with flesh.
Blood painted the battlefield.
A slayer screamed—
"THEY'RE REGENERATING TOO FAST!"
"Focus the necks!"
Another fell.
Then another.
Shizukana moved.
"Insect Breathing: Fifth Form—Phantom Hive."
She vanished.
Multiple thrusts struck at once—
Demons collapsed like puppets with cut strings.
But the legion kept coming.
"Hashira-sama!"
A squad member was grabbed—
*Crunch
"NO—!"
Her eyes sharpened.
But she didn't turn back.
Because—
She couldn't.
"Such emotions…"
Douma descended slowly.
The temperature plummeted instantly.
Frost crept across the ground.
But it wasn't just cold.
It was… hollow.
Emotionless.
Behind him—
A massive aura manifested.
Like a frozen paradise.
Lotus flowers made of ice bloomed endlessly—
Beautiful.
Silent.
Dead.
Each petal reflected distorted light—
Like broken emotions trapped within.
Where Shizukana's aura felt alive—
His felt… empty.
A void disguised as beauty.
"…so delicious."
A chilling aura spread.
"Blood Demon Art: Frozen Lotus Garden."
The ground froze instantly.
Ice spread like death itself.
Several slayers froze mid-motion—
Then shattered.
"Fall back!"
Too late.
The squad was collapsing.
One by one—
They died.
Until—
Only she remained.
"You're alone now."
Douma smiled.
"How tragic."
Shizukana raised her blade.
"I was never alone."
She vanished.
"Insect Breathing: Third Form—Venom Waltz."
Multiple strikes pierced Douma.
He paused.
"…Poison?"
Then smiled wider.
"How cute."
His body regenerated instantly.
"Did you think that would work?"
"I didn't."
She reappeared behind him.
"Second Form: Petal Mirage."
Afterimages surrounded him.
Douma laughed.
"Blood Demon Art: Crystal Bodhisattva."
A giant ice figure manifested—
Swinging down.
BOOM
The ground shattered.
She barely dodged.
Blood trickled from her lips.
Her breathing faltered.
Her body—failing.
Douma tilted his head.
"You're dying."
"…Yes."
"Then why fight?"
She smiled softly.
"For them"
As both of them moved—
Their auras collided.
Poison butterflies vs frozen lotuses.
Life vs emptiness.
The battlefield cracked under the pressure.
Air distorted.
Even the ground seemed unable to withstand their presence.
"Insect Breathing…"
Her aura changed.
Sharp. Final.
"…Seventh Form: Eclipse Chrysalis."
She deflected incoming ice shards—
Advancing step by step.
Douma frowned slightly.
"Interesting…"
She lunged.
"Fourth Form: Monarch's Descent!"
A direct strike—
Piercing his neck.
For a moment—
Silence.
Then—
He smiled.
"You're still not enough."
Her grip tightened.
"I know."
Douma paused.
"…What?"
She whispered—
"I never intended to win."
His eyes widened slightly.
A strange scent filled the air.
Poison.
Heavy. Dense. Absolute.
"All the poison…"
"…within my body…"
"…within my blood…"
"…within my lungs…"
She stepped closer.
"…is yours now."
Douma's expression changed.
"YOU—"
"Insect Breathing…"
Her final smile—
Gentle. Loving.
"…Final Form: Last Bloom – Silent Extinction."
A massive explosion erupted.
Not fire—
Poison.
A storm of death.
Consuming everything.
Silence followed.
For a moment—
Nothing existed.
-
Far away…
Within the collapsing storm—
Something moved.
A faint crack echoed.
Ice.
Thin… but unbroken.
A figure stood at the center.
Barely visible.
Encased in something… unnatural.
Not ordinary ice.
Not regeneration.
Something deeper.
Something… evolving.
A voice echoed faintly—
"…Magnificent…"
A distorted smile formed.
"…So this is the resolve of a Hashira…"
The structure around him began to crumble slowly.
But his body—
Still remained.
"…I must remember this…"
The storm swallowed everything again.
And then—
Nothing.
-
Present – Butterfly Mansion
A crow landed.
Caw
"Message… message…"
Shinobu turned.
Kanae stood beside her.
"…Report."
The crow spoke—
"…Insect Hashira Shizukana Hoshino… has fallen…"
Silence.
"…Killed in battle against an Upper Rank demon…"
The world stopped.
Shinobu's hands trembled.
"…No…"
Kanae's eyes widened—
Then slowly…
Tears fell.
"…No…"
Shinobu clenched her fists.
Her body shook violently.
"…They're lying…"
Kanae collapsed to her knees.
"…She promised…"
"…she said she would come back…"
Memories flooded their minds—
Her smile.
Her voice.
Her warmth.
Shinobu's tears streamed uncontrollably.
"…She left us too…?"
Kanae looked up—
Eyes no longer gentle.
Burning.
"…No."
Her voice was steady.
But filled with rage.
"She didn't leave."
Shinobu looked up.
"She entrusted us."
Shinobu slowly stood.
Tears still falling—
But her expression changed.
"…An Upper Rank…"
Kanae gripped her sword.
Shinobu's voice cracked—
But hardened.
"…We'll kill it."
Kanae nodded slowly.
"No matter who it is."
Their voices overlapped—
Cold.
Then together—
They spoke.
"We will kill him."
No hesitation.
No doubt.
Only resolve.