"Damn it—!"
"Where the hell did I end up?"
"Is this even my country anymore?!"
Before Yasui Ryosuke could process what was happening, a flood of memories was forcibly shoved into his brain, churning violently.
The Meiji era.
Rumors of man-eating demons roaming the night.
A corps of demon hunters—the Demon Slayer Corps—who risked their lives to hunt them down and protect humanity.
This is… this is the world of Demon Slayer?!
Yasui Ryosuke went through the classic stages: first tears, then denial, then—
No, scratch that.
He was heartbroken. Utterly devastated.
Bro—
I still had over a hundred thousand primogems saved and hadn't pulled yet!
No one's guarding Konoha Village now!
I didn't even get to wear my heirloom Liu Tao once!
There were several terabytes of "study materials" still sitting on my computer, un-deleted!
My phone browser history, all those shady fruit apps, Agent-this, World-that—none of it was wiped!
If some cop cracks my phone open—
"My spotless reputation! My honor!!"
Ryosuke howled toward the heavens.
He was a perfectly upright citizen, a blooming flower of the motherland who did good deeds every day. He didn't get hit by a truck, didn't win the reincarnation lottery—so how the hell did pulling an all-nighter and going to sleep land him here?!
Reality, however, proved one cruel truth:
Staying up late really can kill you.
Is performance pressure that bad these days, even for transmigration?!
Good news: Ryosuke had read the original work carefully.
Bad news: He was about to die.
A tearing pain ripped through his body.
Ryosuke convulsed uncontrollably, coughing up mouthfuls of blood.
This body—his predecessor's body—was a terminally ill wreck. Both parents had been eaten by demons. He himself had only survived thanks to an elderly man with a fierce face, a cane, and a single leg.
"So it's already this miserable… System bro, stop hiding and come out already!"
Ryosuke cried out in agony.
A crackling electric sound echoed in his mind.
[Demon Extermination System activated.]
[The host may obtain lifespan by slaying demons to heal illnesses, or consume lifespan to learn Breathing Techniques and sword skills.]
The corner of Ryosuke's mouth twitched. "System…"
"How long do I have left?"
[Congenital liver failure. One year at most. Hee-hee~]
"Hee your damn sister!"
Ryosuke exploded.
Me—
My—
Damn—!
You want this sickly, half-dead body to go kill demons?!
Forget not having a Nichirin Blade—just the idea of spending lifespan made his head hurt!
What kind of sane system makes its host pay with their life?!
Ryosuke roared, "How the hell am I supposed to slay demons like this?! What, with kindness? Hug them until they slit their own throats?!"
[Host, don't panic. At least it's a liver issue, not the lungs. With physical training and Breathing Techniques, you can ease it a little. You'll die slower.]
Ryosuke ground his molars. "Screw you! Which sweatshop factory produced you?! I'm filing a complaint!"
Only static answered him. The system played dead.
Ryosuke spent a full kunchime—about half an hour—forcing himself to accept reality.
What else could he do?
Train. Learn. Fight.
If he didn't kill demons, he would really die!
A deliberate cough sounded from the doorway, cutting off his tirade against the heartless system.
Ryosuke looked up.
An old man stood there—short in stature, yet radiating a steady, oppressive presence.
White hair. White beard. A stern, fearsome face.
Most striking was the scar beneath his left eye, eerily reminiscent of some movie star, and the missing right leg replaced with a prosthetic. He supported himself with a wooden cane.
Thunder Hashira—no.
Former Thunder Hashira.
Kuwajima Jigoro.
A veteran of the Demon Slayer Corps.
A cultivator.
The man who would one day train Agatsuma Zenitsu and… that other one.
Kuwajima's gaze held concern—but far more severity.
"You're a tough little brat. Still breathing, huh."
"Thank you for saving my life, sir."
Ryosuke stood and bowed, though his weak body made the movement clumsy.
Kuwajima tapped his cane forward, eyes sharp as blades as they swept over Ryosuke.
"This body of yours… it's like rotten wood hollowed out by worms. One gust of wind and you'd collapse. You're weaker than this old man. Congenital liver failure, depleted qi and blood. The fact that you're alive at all is a miracle."
Ryosuke: "..."
That hurt, old man.
Did you really need to say it like that?!
"Born with it?" Kuwajima asked.
He frowned deeply. "The Corps' doctors might help stabilize you a bit. Buy you some time."
Ryosuke smiled bitterly inside.
Judging by the memories he'd inherited, this should be the late Meiji era—about ten years before the main storyline.
Shinobu and Kanae were still kids. The Butterfly Mansion didn't even exist yet.
Stabilize? Stabilize my ass.
With this era's medical level, curing congenital organ failure was pure fantasy.
As for becoming a demon…
That trash boss Muzan offered no salary, no benefits, and laid people off on a whim. Modern-day black-hearted capitalists would praise him as a saint!
Even if Ryosuke wanted nothing else and was willing to cross-dress just for eye candy—
The moment Muzan peeked into his memories and learned where the Blue Spider Lily was, Ryosuke would be crushed like a bug.
I'm not even afraid of the sun anymore—why would I need you demons?!
That path was completely blocked. Hard pass.
The reality was simple:
If Ryosuke didn't kill demons, he would die.
One year later—straight to the crematorium.
The system's life-for-power exchange was the only way forward.
Overwhelming survival instinct crushed all hesitation and wishful thinking.
Seeing the shifting expressions on Ryosuke's face, Kuwajima assumed he was despairing, and was about to say something about cherishing what time he had left—
When Ryosuke moved.
He slowly forced himself upright and bowed ninety degrees.
"Coach! I want to play basketball—uh, no, wait!"
Realizing he was on the wrong channel, Ryosuke corrected himself.
"Senior! I want to slay demons! Please—teach me!"