The first thing Ren Takahiro felt was pain.
A heavy, throbbing ache that spread from his head to the pit of his stomach. When he tried to move, the world spun. His eyes cracked open, and all he could see was a blur of trees and dim light filtering through the branches above.
His throat was dry. His chest rose and fell in sharp, uneven breaths.
"Ugh… what happened…?"
The last thing he remembered was the blaring horn of a truck, bright lights, and a loud thud. Everything after that was blank.
Ren sat up slowly, grimacing. The ground beneath him had soft earth covered with fallen leaves. The air was crisp—fresh in a way modern cities never were.
"Where… am I?"
He stood, wobbling a bit. The forest around him looked ancient—untouched. The trees were thick, their roots twisting through the soil like veins. Far in the distance, he could see a small dirt road and smoke rising into the air.
He looked down at himself. Gone were his jeans and hoodie—he was wearing a simple brown kimono, a dark haori, and sandals made of straw. The fabric felt rough but real.
"Okay," he muttered, rubbing his temples. "So either I'm in a coma dream… or I just got dumped in feudal Japan."
That sent a chill down his spine.
He checked his surroundings again. No signs of cars, buildings, or power lines. Just nature and silence.
And then—
---
[Initializing System...]
[Welcome, User: Ren Takahiro.]
[Reincarnation confirmed.]
[Gacha System successfully integrated.]
---
Ren froze mid-breath. "...What?"
The voice wasn't coming from anywhere—it was inside his head. Cold. Mechanical. Completely emotionless.
---
[System Explanation:]
The Gacha System allows the user to acquire randomized talents, abilities, and items from any world.
Complete quests to earn Gacha Tokens.
Rewards are randomized by category.
Failure to complete essential quests may result in penalties, including death.
---
Ren stared into the empty air. "…Okay. So I died. And now I've got a gacha system in my head. Great."
He sighed, dragging a hand down his face. "Figures my afterlife would come with microtransactions."
Still, a spark of curiosity pushed past his confusion. If this was really some kind of second life system, then maybe—just maybe—he wasn't totally helpless.
"Alright, System," he said cautiously. "What's my first quest?"
---
[Quest: First Steps]
Objective: Survive your first night.
Reward: Randomized Gacha Pull (Talent/Ability/Item)
Penalty: Death.
---
Ren blinked. "...Survive the night? That's vague. What, is there a bear around here?"
The System didn't respond.
He sighed again, glancing up at the sun already dipping toward the horizon. "Well… looks like I'm about to find out."
He followed the dirt path he'd spotted earlier, hoping it might lead to a village. After about half an hour of walking, the forest opened up into a small clearing where a few wooden houses stood. Smoke rose from one of them, carrying the scent of cooked rice.
The people there were dressed like farmers—simple robes, headscarves, straw hats. They looked poor but peaceful.
When one of them spotted him, an old man with a hunched back stepped forward.
"Traveler?" he called out warily. "You're far from the main road. Where are you heading?"
Ren hesitated. "I… honestly don't know. I woke up in the woods."
The old man squinted. "Got lost, then. Best not to wander after sunset. Bad things come out when the moon rises."
Ren tilted his head. "Bad things?"
The old man's expression darkened. "You'll hear stories, but some say monsters walk the mountains. They come for stragglers after dark."
Ren forced a nervous laugh. "Monsters? You mean, like—wolves?"
But the man didn't smile. His face was grave. "Wolves don't howl like these monsters."
A chill ran down Ren's spine. The man bowed slightly and returned to his home, leaving him standing in the fading light.
He turned toward the dark forest again.
"...Monsters that hunt at night, huh?"
Something about that sounded eerily familiar.
But before he could dwell on it, a sharp tone rang in his head again.
---
[Quest Update: Survive until morning.]
[Progress condition triggered: Nearby threat detected.]
---
Ren's pulse quickened. "Nearby… threat?"
A sudden gust of wind rustled the trees. The villagers had all gone inside. Only the chirping of insects filled the silence.
Then he heard it.
A soft, wet dragging sound.
Ren spun around—and froze.
A figure was crawling out from between the trees. Its limbs were too long. Its fingers ended in claws. Pale skin glistened under the moonlight, and its mouth stretched into a grin far too wide for a human face.
Blood dripped from its lips.
Ren's heart stopped. "…That's… not possible."
The creature tilted its head, eyes glowing faintly yellow. "Ah… I can smell you. Fresh."
It wasn't until that voice—low and almost amused—reached his ears that Ren realized what he was looking at.
A demon.
The realization struck him like lightning. The way it moved, the smell of iron, the monstrous grin—he'd seen it before, countless times on a screen.
But now, it was real.
And that could only mean one thing.
"I'm in… that world," he whispered, eyes wide. "Demon Slayer aren't I..."
The demon's grin widened. "Oh? You know about us?"
Ren took a shaky step back. "Yeah. Unfortunately."
---
[Emergency Quest Triggered!]
Quest: Defy Death
Objective: Deliver a critical strike to the demon before dying.
Reward: Randomized Gacha Pull (Talent/Ability/Item)
Penalty: Death confirmed.
---
Ren's instincts screamed at him to run—but his legs wouldn't move.
The demon lunged.
Ren dove sideways, the claws grazing his arm. He hit the ground hard and scrambled to grab anything nearby. His hand closed around a sharp branch.
The demon turned toward him, smiling like a predator toying with prey. "Fight back, little human. I like it when they struggle."
Ren's breath came fast and shallow. He gripped the branch with both hands. "System—anything I can use!?"
---
[Inventory: Empty.]
---
"Figures!"
The demon charged again, faster this time.
Ren ducked low and, with all the strength he had, thrust the branch forward—straight into its face.
A wet crunch. The branch pierced through one of its eyes.
The creature screamed, staggering backward and clawing at its face.
Ren gasped, falling to his knees, every nerve in his body on fire.
---
[Quest Completed: Defy Death]
Reward: 1x Gacha Token (Talent Category)]
---
The demon straightened, blood dripping down its cheek. Its remaining eye glowed brighter with rage.
"You'll regret that, human…"
Ren barely managed to stay conscious, his vision blurring. He had seconds, maybe less.
"System… use it!" he shouted hoarsely. "Use the token now!"
---
[Rolling Gacha...]
[Category: Talent]
[Reward: Sabito's Swordsmanship Talent]
---
Ren didn't understand at first. But then—his breath hitched.
A rush of knowledge and movement flooded into his mind. Stances, footwork, breathing. The image of a boy in a fox mask, his blade flowing like water, filled his vision for just an instant.
His body moved before he realized it.
He grabbed the branch again and stood, his breathing suddenly steady—calm.
The demon blinked, momentarily confused. "You… you changed."
Ren lowered his stance. His legs adjusted naturally, like his muscles had done this a thousand times before.
He inhaled deeply—then exhaled, his motion smooth and deliberate.
His body flowed forward like a current. The branch slashed across the demon's neck.
The creature shrieked and stumbled. The force wasn't enough to decapitate it—but the precision was terrifyingly exact.
Ren didn't let up. He struck again and again, every swing cleaner, faster, sharper. The rhythm was instinct now. Some swings were used to parry the demons claws but still Ren could just barely hold on due to his lackluster equipment and physical condition.
And then—the first light of dawn touched the forest floor.
The demon froze, eyes wide with horror. "No—no, not sunlight—!"
The demon tried running but Ren expecting this jumped into action and blocked the demons escape route.
Ren staggered back, watching as its skin began to smolder, then burst into ash from the sun.
When the last ember faded, silence fell again.
Ren dropped the broken branch, panting heavily.
He had done it. Somehow, he had survived.
---
[Quest Completed: First Steps]
Reward: 1x Randomized Gacha Pull (Talent/Ability/Item)]
[Bonus Condition Met: Beginner Demon Slayer Mark Potential Detected (Unawakened)]
---
Ren collapsed against a tree, his whole body trembling.
He didn't fully understand what had happened—but one thing was clear.
He wasn't dreaming. He wasn't hallucinating.
He had really been reincarnated into Demon Slayer.
And the only reason he was still alive… was because of this strange System and the talent of a dead boy named Sabito.
Ren looked up at the rising sun, a faint, tired smile on his face.
"Guess this is my new life," he murmured. "Fine then… may as well make the most of it."
-
This is my first story, I have recently finished Demon Slayer and with it I've wanted to write my own delusions for a fanfiction. Please be patient with me and there's any changes or recommendations that you believe will help then please do share it.
Also at the current moment the love interest will be Shinobu. The love will be a much more side plot thing and not the main focus. If you don't like Shinobu then make some other suggestions and there may be a change.