Demon Slayer AU

By: FunahoMisaki

(A/N: I own nothing and it was just a little blurb that hit me so I had to write it. Maybe a bit OOC.)

"Really Giyuu-san? Agreeing to slit open your belly for this boy and his demon sister?" Shinobu asked looking at Giyuu who merely nodded his head.

"I wonder what your friend would say. How is he?" Shinobu asked and the others winced at that since they knew who exactly she was talking about.

"I don't have a friend." Giyuu said completely blank faced and making Shinobu giggle a bit while Tanjiro looked upset.

"I know. Just reminding you." Shinobu said and a few of the other Pillars winced while Tanjiro frowned heavily at that as he stared at Shinobu.

"Okay." Giyuu didn't even change his facial expressions before he turned to look at her.

"How's your sister?" Even Muichiro's eyes widened and he gaped at Giyuu at that while a miasma of rage surrounded Shinobu and Tanjiro looked at him stunned and upset now.

"Holy shit dude did you kill her?" Obanai asked wide eyed behind his mask as he stared at Giyuu while Tanjiro looked distressed.

"G-Giyuu-san?" Tanjiro had tears in his eyes and he as trembling as he stared at Giyuu who went wide eyed and everyone saw a hint of panic on his face.

"W-Why would you say something that mean?" Tanjiro asked staring at Giyuu heartbroken and Giyuu was immediately standing and pulling the boy into his arms and petting his head.

"I'm sorry. I swear I didn't mean it. She just does this to me all the time and I thought I'd let her see how it felt for once. Don't cry Tanjiro-kun." Giyuu said and he was panicking slightly because he heard the small growl coming from within the box aimed at whoever had made the tiny basket imouto's precious big brother upset.

"Shinobu-san is so mean to Giyuu-san all the time?" Tanjiro asked staring wide and teary eyes at Shinobu now and her eyes widened and her miasma of rage vanished as she stared at the boy who suddenly looked a hell of a lot younger now.

Giyuu turned his head enough to give her a dangerous glare as he had a miasma of rage around him for the first time they could all remember and everyone shivered at the power this boy had over the Water Pillar.

But the distressed and upset look Tanjiro was giving her made her heart break. He reminded her of a kicked puppy or kitten or other small cute animal that shouldn't be harmed.

"I'm sorry. I don't know how to mess with him without being mean. I promise I don't mean anything by it." Shinobu said standing and going to try and comfort Tanjiro as well while looking helplessly at the others for help.

"The others…they don't stop you or teach you better?" Tanjiro now turned his teary eyes onto the other Pillars and there was a growling and scratching noise from the box.

"We're sorry kid but we don't know how to teach her better. We thought she was mature enough to know better and she doesn't listen when we try and talk to her about it." Mitsuri said gently as she stepped over and patted the boys head.

"But…But Giyuu-san has friends right? I thought I was your friend…" Tanjiro said looking upset as he stared up at Giyuu who immediately petted his head again.

"You are my friend Tanjiro-kun. I promise you're my friend. I know you don't hate me or anything like that. She just didn't know we were friends." Giyuu assured the boy while Shinobu looked distressed as she rubbed at his back.

"I'm Giyuu-san's friend I think." Muichiro said as well as he stepped over and poked Tanjiro's nose.

"Yes I thought we were friends as well!" Rengoku said loudly and he looked to be one of the most distressed by Tanjiro's crying, after all he had a younger brother who was around Tanjiro's age.

"He's alright I guess." Sanemi said shrugging and trying not to show how much Tanjiro's upset looks affected him. God it was worse than the boys headbutt.

"See? She was just teasing me about it. She didn't mean it. I promise she's very nice when you get to know her." Giyuu said making Tanjiro wipe at his eyes and nod his head, giving them all a bright smile that was pure sunshine and cheer.

"I'm glad to hear that. I was so upset with what you two had said to each other. I should have known it was your way of teasing him and his way of showing he didn't like it." Tanjiro said and the sheer sunshine he was emitting was near enough to blind them all even as Muichiro quietly asked Mitsuri if she knew Shinobu could be nice.

The growling and slight clawing sounds from the basket calmed down and stopped now that he was no longer upset and Shinobu patted Tanjiro's head a bit now, Mitsuri and Muichiro shortly behind her.

"We're sorry. We should have known better than to say things like that around someone who doesn't know us." Shinobu apologized quietly to the boy who smiled brightly at her and honestly she wondered if his smile could cause her to have sunburns.

"I'm just glad that you two don't actually hate each other that badly. I'm sorry if I overreacted." Tanjiro apologized with a bow and Giyuu patted his head again in reassurance.

"Dibs." Muichiro said after a second of silence when Tanjiro tried to move away from them all, only for them to hold onto him tightly.

"Hey what do you mean dibs?" Obanai asked glaring at the boy who looked half a second away from floating off into space with how dazed he usually was.

"I'm keeping him. He can learn to be a pillar from me. I call dibs." Muichiro said as if it were obvious and the others began to protest slightly.

"I heard he was able to use Flames despite being trained in Water Breathing. If anyone should train him into being a pillar I think I should be the one to do so." Rengoku said, his voice just as loud as always.

"Oh that? I have no idea how I did that. I just used a dance move my dad taught me before he died out of instinct." Tanjiro said smiling sheepishly at Rengoku and the others stared at him for a moment. A move that was from a dance his dad had taught him? And he used it in battle despite being trained in a completely different style?

"Dibs." Muichiro said again and there were a bit more protests this time.

"He's a Water Breather. Anyone who wants to try and take him from me…" Giyuu slowly drew his sword as he glared death at them all, a miasma of darkness and power flowing from him that effected everyone but Tanjiro.

"Wah! Why are you about to fight?!" Tanjiro seemed completely oblivious to why they were about to come to blows as he tried to calm them down.

Kagaya just sat there beside his son enjoying his tea.