Muzan x sister reader

What

The hashira's each entered, individually surprised at the room, except for Tanjiro and Sanemi.

"Ok!~ let's all sit around here!~" Y/n announces, pointing at the table.

She slips to the kotastu and sits down just beside Sanemi.

"Go to another sit, brat" Sanemi tells her.

Y/n pouts and smacks his head, sending his face to the wooden table, "Oh don't be like that San San!" She whined.

Sanemi grunted as he moved his face up, "San San...? Who the he'll is that?" He asked her.

Y/n glared at him playfully before smacking his head again on the table, creating a dent from the force. "Eh? Did you lose common sense San San?! Who else but you!" She exclaims.

The other pillars stared at him, pitying him inside their heads. Shinobu then notices the shelves, "Y/n-san? What are those book?" She questioned Y/n

Y/n glanced to the insect hashira and smiles, "They're my diaries from the past hundreds years of life! Wanna read them?" She asked her, clearly knowing that Shinobu has a thing for information.

Shinobu smiles, "Gladly" she says as she stepped towards the shelf.

Y/n turned to the others, "You all can get one too! Be sure to return it though!" She orders.

They nodded before going to the shelf and grabbing a random book.

Once successfully grabbing one, they all took their sits by the table.

"I-is it really ok to look through these? T-they're diaries af-after all..." Zenitsu timidly asks, glancing at the book in hand.

He flinched when Y/n only smiled at him sweetly, "Don't worry Zenitsu-kun! I don't really mind!" She giggled.

Y/n turned to the white haired male beside her and tapped his shoulder. He glances up, "What is it--

Suddenly, Y/n forces a ohagi in his mouth and pushes the diary that he personally read yesterday night.

"That's the same diary you read yesterday, so don't worry. I even placed a bookmark on where you last were" she states to him before pulling a teapot and cup behind her and filling it with tea.

She then does this with every cup and pushed it infront of a everybody.

"There we go!~ now just ask me if there's anything you want to know--

"Where's Muzan Kibutsuji's base!?" They suddenly all asked, staring at her expectantly.

Y/n grimaced at their actions. "Sorry, but I'm afraid I don't know the answer to that" she smiled.

They all sat back and sighed in defeat. Pitying them, she grinned.  " Buuuuuuuuut~"

Tanjiro raised a brow, "But? He asked as the other's glanced back to the female demoness again.

"I got random memories...or it may be called as glimpses?" She says.

This gets their attention, and turned to her.

"Please tell us more, Y/n-sama" Gyomei tells her, intruiged.

Rejoicing at getting their attention, she smiles. "Ok so, sometimes I'll randomly sleep. No matter if I'm standing up or not" she explains.

"But...you haven't done that when we saw you" Obanai says.

"Yeah, even last night" Sanemi adds.

Y/n nodded in understanding but raises a hand, "Yes yes, I know. But that's what's weird"

"What's weird?" Mitsuri asks.

"The fact that I don't get them anymore, it stopped around when Tanjiro-kun came" she tells them.

The pillars glanced at Tanjiro who was confused as they were.

"Never mind. The base is somewhere around--

Suddenly, Y/n stopped in the middle of her sentence. Her eyes wide as she struggled to let out the words.

Shinobu casts her a worried glance, "Are you alright, Y/n-san?" She asked.

They watch as Y/n places her hand back to her lap and bit her lip. "I-im sorry...i-it seems that the curse e-even affects m-me..." she stuttered.

It was as if magic, she suddenly changes and smiled at them as if nothing happened.

"What did you mean by earlier?" Giyu asked her.

Y/n tilts her head, "Earlier? Did I say anything--oh! I said something about the base noh?" She stated before hitting her head.

"Geez Y/n! I can't believe you'd try saying about Onii-sama's base!" She talked to herself in a childish manner.

They realized the way she spoke and intruiged Shinobu yet again. "Y/n-san? Do you have split personal

Y/n looked at her with eyes twinkling like starlights, it was unlike earlier which was balanced.

Suddenly, the girl smiles and nodded profiously, "Yep! Yep! Yep!" She exclaims, agreeing to the fact

Her eyes suddenly caught sight of Nezuko and gasped. "Kyaah! Onii-sama is gonna be sooo happy when he gets his hands on you!!" She giggled pointing at the pink eyed girl.

They furrowed their brows at her, "What do you mean, Y/n-san?" Tanjiro asked, covering his sister with his arms.

Y/n smiled at him, "She can--

Her eyes then began to go dull and she sat back.

"Y/n-san?" Tanjiro called out.

They were all confused to what's happening. A curse and split personalities.

Y/n smiled at them calmly, "Sorry about that. That's my child persona. She quite a chatter box you see" she states.

Grabbing the plate that laid beside her, she places it on the table." Here, you guys can eat these~" she tells them as she pushed a plate of mochi's.

They nodded, only one thing in mind.

"What's happening?!"