The demon's claws gleamed a dull blue-gray under the moonlight.
Locking onto the young man's back, she kicked off the tree trunk, launching forward like an arrow—
But in that instant—
Sui's blade was already at her throat.
The demon froze.
Lightning illuminated her face. Veins bulged like centipedes, bursting under scattered arcs of electricity as blood splattered.
The white-haired youth heard the air split with a piercing shriek.
A crimson haori fluttered like butterfly wings in midair.
Lightning exploded from her step, illuminating the entire forest.
Her eyes were closed—
Peaceful.
Beautiful.
And yet—
Her hand rested on the hilt.
The demon had no time to fear.
No time to react.
Because lightning was faster than everything.
The blade passed her neck—
A clean arc.
Blood followed a moment later.
Her expression remained twisted in a scream as her head spun through the air.
Sui landed lightly.
Sheathed her sword.
Click.
Only after the crisp sound of the blade returning to its scabbard—
Did the dull thud of the head hitting the ground follow.
"…How… Did you do that?"
The demon's final words came out in a daze.
No one answered.
"…You…"
The young man struggled to speak.
Too fast.
Everything had happened in an instant.
Her form—
Perfect.
Exactly what Thunder Breathing should be.
Rare, yes—
But when it appeared, it was something demons would fear instinctively.
"What is it?"
Sui turned slightly.
Moonlight brushed her profile like polished crystal.
The young man stepped forward, checking the corpse.
It was already burning.
Dead.
He let out a breath, planting his bloodstained cleavers into the ground.
Leaning against a tree, he wiped his face.
He had hunted demons before—long before joining the Corps.
But this one—
It was on another level.
And yet—
She had ended it effortlessly.
He glanced at her.
She was wiping her scabbard with her sleeve—
Even though not a single drop of blood had touched it.
"Hey!"
His voice was rough, still edged with tension.
"That skill of yours… you've killed at least thirty demons, haven't you?"
"I've heard that puts you at Kinoe or Kinoto level. Not far from Hashira."
"When did the Corps start sending Hashira candidates as examiners?"
"Or did you already know something like that would show up here?"
His thumb ground against dried blood on his chain.
Compared to her—
He felt weak.
And he hated that.
Sui lifted her blade, fingers brushing the golden guard.
Moonlight settled along her brow as she smiled faintly.
"That's a bit harsh."
"I'm just a trainee who hasn't even earned a uniform yet."
"Don't joke around!"
He inhaled sharply.
"That was Thunder Breathing, First Form: just now, wasn't it?"
"That level of power—you'd need at least five years of training!"
Even that estimate felt low.
Thunder Breathing wasn't something you mastered easily.
And yet—
Here she was.
Unreal.
Sui covered her mouth, feigning surprise.
"Oh my… to think the young man I saved would be so rude."
"…What did you say?!"
He snapped—
Then I froze.
A faint floral scent filled his lungs.
He realized—
They were standing very close.
Close enough to see her long eyelashes.
He jumped back instantly.
Turning away, he spoke stiffly:
"…Sanemi Shinazugawa."
Sui nodded lightly.
"Sui."
"…No surname?"
"I was raised by a shrine maiden. I don't have one."
Sanemi frowned.
"You're really just a trainee?"
"Mm."
She tilted her head slightly.
"Thunder Breathing isn't well known in the Corps right now."
"As for talent… perhaps the thunder gods favor me?"
"Like how some people are born carrying the scent of a storm."
Her gaze drifted toward his torn sleeve.
The jagged edges—like something ripped apart by wind.
Sanemi went quiet.
"…After I pass."
"No—after I get my Nichirin blade…"
Leaves rustled in the silence.
Sui sat calmly as one landed on her haori.
She heard him take a breath.
"Where do you live?"
"Hmm?"
"I said your place!"
Sanemi's voice hardened.
"You're the former Thunder Hashira's disciple, right?"
"Then you're at Kuwajima's dojo."
"When this damn test is over… I'll come find you. With a wooden sword."
"I'll repay what I owe."
Sui smiled faintly.
"Asking for a girl's address? How bold, Mr. Shinazugawa."
"…That's not—!"
He faltered.
"I don't like owning people!"
"I'm not treating it as a favor."
His words hit nothing.
Like punching air.
"Once I pass, I'll be sent on missions," Sui said lightly.
"You won't find me at the dojo."
Before he could respond—
She was already gone.
…
Eyes filled with hatred.
Sui recalled his expression.
Beneath the rage—
There was loneliness.
That wasn't rare among Demon Slayers.
But he was different.
She didn't need sight to see it.
His potential—
It was like a storm.
Violent.
Destructive.
Yet at its center—
A fragile calm.
She wandered the mountain until dawn.
No more demons appeared.
Her blade hovered midair, a drop of dew forming at its tip.
Behind her—
Sanemi stood.
His chains bound three demons, hanging them from branches.
Before joining the Corps, this was how he killed them—
Without a Nichirin blade, he let the sun do the work.
Even now, he preferred it.
The sunlight was crueler.
More painful.
He liked listening to their screams at sunrise.
He kicked aside a branch, sparks flying from his weapon dragging along the ground.
"There are no more demons here."
"The thing you're looking for—southwest."
Sui's crimson haori swayed.
She stood in the sunlight.
He remained in shadow.
"…What do you mean?"
"Don't play dumb, you scheming woman."
Sanemi snorted.
"You've been circling the mountain trying to figure out why something like that showed up here."
"You came near me on purpose."
"Using my Wind Breathing to track direction, right?"
Sui smiled.
"Caught."
"…Want to team up?"
"Don't get ahead of yourself!"
He slammed his fist into a tree, shaking loose leaves.
Sunlight spilled over the demons as they screamed.
"I hate people like you—always scheming like nobles!"
"…Shrine maidens count as nobles?"
She actually paused.
"Girls from shrines have no self-awareness!"
"You sit there all day, taking offerings, money—never thinking about how people like us survive!"
"If praying to gods worked—my bastard father would've been dead long ago!"
…
Silence.
Too long.
Sanemi's chest tightened.
…That was too much.
She hadn't done anything wrong.
And she'd saved him.
"…Damn it."
He ran a hand through his hair, frustrated.
He wasn't good at this.
Never had been.
Then—
She spoke.
Softly.
"…You're right."
"Praying to gods doesn't do anything."
Her tone hadn't changed.
Still calm.
Still gentle.
"So…"
She turned slightly.
"Why not try praying to me?"
A faint smile.
"After all—"
"I really can kill them all."
Sanemi didn't reply.
But he didn't argue either.
He looked up.
She stood against the rising sun—
Bathed in gold.
"Want to witness it?"
Her voice was light.
"Not to brag—"
"I'm basically a messenger of death."