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English
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Published:
2025-03-04
Updated:
2026-06-17
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7,895
Chapters:
5/?
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Blood in the Water

Summary:

How could the afterlife have possibly led to this?

OR

Saneobagiyuu modern au where Giyuu is a ghost haunting the apartment Obanai and Sanemi just moved into. The duo meet ghost Giyuu and promptly freak the hell out, and upon finding out that he was a missing person in a large serial killing case; said cold case is blown wide open. The two aswell as their friends begin to investigate Tomioka's death and the deaths of his companions, both to bring rest to his spirit; and protect Tanjiro Kamado—who may be the very next victim of the Fox Hunter.

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A/N;

Each posted chapter will contain 2 chapters from my planning document to make the posts longer :3
Im currently working on how to format my writing to be lengthier so I hope my growth is shown as I continue with this fic!!

Notes:

PLEEEAAAASSEEEEEE make sure you read the tags, I know everyone says that but at the very end I have the trigger warnings! These thigns wont be in EVERY chapter or anything, but they will come up as the story goes along. (I will also put a TW on the chapter they appear in so dont worry about it popping up out of nowhere) Also sorry if some details change, im still ironing things out--such as who lives and who doesnt before the story even begins—so things may change and I apologize for that; I will go back and edit out various kinks as I continue the fic. :3

(See the end of the work for more notes.)

Chapter 1: Startled from the Coma

Chapter Text

Crisp fall air howls outside the rickety apartment building. A full moon shining behind thick dark clouds, barely visible against the pitch black night sky. A storm is quickly brewing. On the third floor, apartment 306, a group of nine teenagers sit in a large circle, surrounding an ouija board. Zenitsu nervously clings to Tanjiro, Inosuke arguing loudly with Aoi, Kanao silently keeping track of everything, Nezuko not quite paying attention, Senjuro in contrast paying too much attention, Muichiro placing bets with Genya and egging him on, and Tanjiro-the voice of reason-very much does not want to disturb any spirits. Sadly, to the dismay of about half the group, Genya, Inosuke, and Muichiro each place a single hand each on the planchette. All the lights in the apartment are off, and a little warm glow is provided by candles and the occasional strike of lightning.

“Guys, we really shouldn't be doing this.. how about we play a board game or something instead?” Tanjiro politely suggests, before immediately having the notion shut down by Aoi who raises a flat voice. “You know what happened last time we tried to play board games together, Tanjiro.” Inosuke laughs proudly and Senjuro shakes his head with a soft sigh at the memory of--to no one’s surprise, Inosuke, throwing a metal Monopoly figurine through Tanjiro’s living room window.

“C’mon, it’s not like anything’s gonna happen, you guys!” Genya says with a soft smile, to which Inosuke rather rudely pushes him away by the face. “Lemmie see that wooden thing! The planet!”

“Planchette.” Zenitsu quickly corrects- to which Inosuke throws the planchette at him and he shrieks. Aoi quickly begins to scold the duo on their noise level, as the two adults in the apartment are trying to sleep-as well as their neighbors-when Kanao places a hand on the planchette silently after picking it back up and putting it on the board again. With a dull, almost bored voice Muichiro asks, “Is there anyone here with us?”

There’s a stunned silence for a suffocating moment as the planchette is slowly guided to yes.

“Did you do that..?” Genya whispers, Kanao shakes her head and Muichiro mumbles a no. Genya rips his hand away from the planchette as if it had burnt him, Muichiro immediately smiling wide. He asks, almost excitedly, “How many of you are in here with us tonight?”

The nine teens, some, such as Zenitsu, stare in horror as the planchette is slowly guided to the number one, to which Muichiro deflates a little, before Kanao softly speaks. “What’s your name?” There’s a long pause before a name is slowly spelled out.

“Tomioka?” Muichiro asks, raising an eyebrow, glaring in concentration as he stares off into space, Inosuke quickly barges back into the conversation and yells, “Are you evil, Bomipolka!?” Genya gives a quick look to Inosuke and mumbles, “I swear you do that on purpose, dude..” And just as the planchette begins to move a flash of lightning strikes, and all the candles blow out at once. The planchette being thrown to the floor, and a pair of ghastly bright blue eyes peering into each of the teenager’s faces.

Genya, Aoi, Zenitsu, Tanjiro, and Senjuro all scream, Zenitsu diving and running across the room. Aoi rushes to grab something, anything, as Tanjiro dashes to be in front of his sister. Senjuro nearly passes out from the shock and starts coughing as he tries to catch his breath and lower his heart rate, frozen. Genya scrambles to his feet and starts running to his older brother’s room. “NEMI!?!”

The light suddenly flicks on and Genya falls to the floor with a thump, having run into something, the teenagers each cringe at the sudden light but all turn to the left to see a rather pissed-off looking Sanemi standing in the room with his arms crossed, and an exhausted-looking Obanai standing in the hallway with his eyes still shut and short choppy hair tangled, looking more annoyed than anything.

“What in the hell are you all doing this late!? I thought we told you to stay quiet!”

Zenitsu quickly and in a panic pipes up, “YOUR APARTMENT IS HAUNTED!! YOU HAVE A HAUNTED APARTMENT!! HOW DO YOU NOT KNOW THAT BY NOW!?” Senjuro cringes at the eccentric blonde's screaming and a vein pops out of Sanemi's forehead as Obanai stumbles back into the hallway behind him, choosing to ignore the situation with a low grumble.

“You're joking.”

 

Sunlight cascades into the room, soft yet blinding. The room is chilly, a dull shiver would go through anyone when they first walked in. Undead eyes stare, wide, out the open window. The sun.. the street... the coffee shop around the corner with that hobo that sells trinkets he finds- oh holy shit he’s still hanging around there?

The spirit-Tomioka Giyuu-gazes out of the window of what once was his apartment’s bedroom. It’s the first time he’s seen anything but a void and the nightmares of his past in... what year is it now? How old would he be if he was still alive? He died on his twentieth birthday, yes, but.. how long ago was that now? Does it even matter anymore? He has no idea if... regardless, it seems he’ll never see him again so he shouldn’t think on it. He blankly stares, focusing on the outside world for the first time since the night of his death, unknowingly almost three years ago now. Unbenounced to him, however, one of the two that now occupy his old apartment begins to stir.

 

Sanemi yawns silently, aggressively rubbing his face with his right hand. For a split second he contemplates going back to sleep before sighing, knowing he’d just be trading tonight’s sleep for it instead. He walks into the kitchen of his apartment and opens the blinds, cringing a bit at the bright light before quickly making himself a large cup of coffee. Mentally, he goes through his to-do list as he does so. ‘I’ve got to finish that essay before lunch so I can turn it in early, have to share the Statistics notes with Kanroji since she was out sick last Thursday, I should check on Genya and the others back home and make sure Ma’s doing good.. gotta head to the gym by four, have three lectures to get to, gotta go to the store soon for safe foods for Obanai..’ He sighs again, as he walks down the hall to his and Obanai’s shared office. Sanemi loves his life right now, yes, but he’s busier than a bee, and-

Sanemi chokes on his coffee and stops dead in the office doorway.

Is that a fucking man!?

Sanemi blinks a few times in complete and utter disbelief, his eyes wide and temper quickly rising. A man-a translucent man, at that-floats with his back to the door, staring out the open office window. From what Sanemi can see, the man has long tangled and matted black hair that curls ever so slightly at the ends, his skin pale, he wears a soft pastel blue kimono that's been torn and distressed; it looks like someone tried to rip it off of him. Sanemi quickly mutters with a shiver, why’s his office so cold all of a sudden? “What the fuck..” The figure turns, tired bright sapphire eyes stare into wide lilac ones. A trail of blood coming from the man’s nose, bleeding scratch marks on his chest half-covered by the lopsided kimono, a third of it yanked down and clinging to his elbow level. The belt of the kimono undone and lying lazily at his side, a matching blood trail comes from his slightly-agape mouth. Blood smudged all over him, staining his clothes in patches. The figure tilts his head to the side, his eyebrows furrow ever so slightly. Confusion obvious only through his eyes, and no other feature.

Sanemi slams his mug onto his desk and snaps, “Who the fuck are you!? What are you doing in my apartment!?”

The man’s eyes widen, his voice soft and scratchy, it makes Sanemi wince, it sounds like it would be painful. “You can see me..?” he asks. Sanemi immediately growls back, “Of course I can fucking see you, you crackhead! Why the hell are you in my apartment!? How did you get in!?”

The man stares, he stares for a long few moments before Obanai hobbles into the room with a groan, holding a hand to his eyes and already wearing a mask. “Shinazugawa, classes got cancelled because of the storm on Saturday. Kanroji is insisting everyone meets her for a get-together-” Obanai doesn’t get the chance to finish his thought as he looks up and spots the man in their office. “What the fuck?” He hisses, venom seeping into his tone, but then he pauses before he turns to Sanemi with a sigh and a lighthearted glare.

"Sanemi. I know you’ll occasionally bring someone back, but it’s too early in the morning-"
"WHY THE HELL ARE YOU STARTING WITH THAT!?"
"There’s a man I’ve never met in our office who looks like your type."
"I DON'T KNOW WHO HE IS!!"
"WHAT DO YOU MEAN YOU DON'T KNOW WHO HE IS!?"

Giyuu didn't even get the chance to open his mouth.. They talk so fast and so loudly, throwing clever insults and loud swears at each other like cannon fodder.

With a moment of peace in daylight, after who knows how long, he can finally look around the room. It looks to be an office, a messy one at that. Heavily used textbooks and notebooks are strewn across half of the floor, color coded tabs in nearly all of them. There are two desks, despite the room being small. One very noticeably neater than the other. The first, on the front wall, a beat-up light cream colored wood desk dons a drawer that cant close, papers thrown across its entire surface half-hazardly, everything written in red ink. A beat up laptop charging in the corner of the desk. The other desk is neat, almost obsessively so. Not a paper out of line, pens color coded and in little ceramic cups to hold them. Books stacked neatly by subject, the desk itself is a stark black color and looks relatively new. A shiny laptop sits in the center of the surface.

Before Giyuu can ask anything, or comment, hell even introduce himself, all eyes are back on him. He turns to look back at the duo in the room. They're glaring at him, why're they glaring at him? Oh, right, a strange man is in their apartment that.. neither of them know. His apartment? He doesn’t even really know anymore.

Sanemi and Obanai both glare flaming daggers at the figure- the ghost? Is this what Genya and his friends were talking about over the weekend? Regardless, Obanai takes a step forward, audibly furious, poison swirling from his throat straight to his words. “What on earth are you doing here? And why the hell are you such a mess?”

The man speaks, to which Obanai recoils in shock at his voice. “This.. is my apartment. I live here. Or... well, I guess I used to.” He speaks slowly, as if even he doesn't know what he’s saying. And to the shock of the duo in the room, the ghost floats weightlessly towards them. He stays silent, Obanai backing up two paces with a scowl, Sanemi growling, “Is this some kind of fucking joke?”

The man slowly shakes his head before speaking again, “I’m Giyuu Tomioka, you can ask the landlord about me, my lease should still be on file.” The duo look at each other in anger and confusion before Obanai rips out of the room and back to his bedroom. Sanemi simply glares at the man who seems to stare blankly at everything. A product of death maybe? It’s then Sanemi notices how there's a black bar around the man’s neck, akin to how people’s faces on television are censored to protect their identity. He looks from a few different angles, to no avail, the spirit raises his right hand to his neck and speaks once more, “I apologize that the stain of my blood isn’t out of the carpet in here after all this time.”

Sanemi’s gaze quickly snaps up, “What the hell are you-” he begins, before he spots it, the slightly present large stain in front of the window, what must have once been deep maroon now slightly red but more brown as it has been scrubbed into the carpet fibres; attempted to be erased. Sanemi’s eyes go wide and his stomach begins to churn. “This isn’t fucking real. The landlord told us that its wine from a previous tenant.” The ghost slowly shakes his head, he opens his mouth to speak again before there’s a shouted ‘What!?’ from the living room. Sanemi quickly turns on his heel and runs into the living room, the ghost peering out of the doorway. “Iguro?! What happened!?” He quickly searches Obanai’s pale face, his roommate’s eyes wide and filled with rage, an all-too-familiar sense of disgust mixing with it. Obanai slowly turns, seeming almost horrified, “The last tenant before us was Giyuu Tomioka, a missing person.”

Sanemi’s eyes widen and his mind goes blank, he doesn’t know what to say, what to think. There’s a hum in that same annoyingly calm voice. Sanemi and Obanai both snap their attention back to the elephant in the room, Obanai quickly flinching away at the ghost’s close proximity to him. Obanai walks over to Sanemi and hands him his phone silently, and right there in the texts between Obanai and their landlord, is a photo of the contract and tenant information- lining up with what the spirit has been saying.

“I’m calling a priest.” Obanai rushes out, snatching his phone back, only to have it shoved out of his hand by his friend who snaps back, “You are NOT calling a fucking priest, Obanai.”

Giyuu floats and stares at the bickering two, they're arguing about what to do about him. Maybe returning wasn’t such a blessing after all, he’s still a burden even in death- can’t he do anything right? An aggravated sigh snaps Giyuu out of his thoughts, he looks to Obanai who’s pinching the bridge of his nose. “Fine, fine. What do you propose we do then?” Sanemi shrugs, occasionally glaring back over at the spirit across from him. “What the hell does someone even do in this situation?”

The two pause, as they seemingly realize something at the same time.

“Ugh, goddamnit..” Sanemi grumbles, Obanai groaning wordlessly, Giyuu looking back and forth between the two simply confused. The duo speak in sync.

“Uzui.”