Sabito's Little Sister

Butterfly Mansion

"Why are they only nice to you?!"

"You should really apologize for that!"

"I'll never forgive you for all my life!"

You sighed as the Kakushi continued yelling at Tanjiro, and a little bit at you. However, since you were close with the Hashiras, they were worried that you actually had high authority. "Hey, no need to yell at him." The Kakushi immediately stopped.

You got to the Butterfly Mansion and went to the back. "Hey Kanao, can we come inside?" She looked at you and nodded. You motioned for the Kakushi to bring Tanjiro and Nezuko inside as you walked over to Kanao.

"Where's Aoi?" She pointed to the door, where Aoi was standing in the doorway. "Hey, Y/N. How was your last few missions?" You sighed. "To be honest, it was hard sometimes and a bore in another." She chuckled and waved her hand. "Come on, the boys are inside."

Almost the moment you stepped inside, you were crowded by three small girls. "Y/N!" They all embraced you, leaving you in a tight hold. "Girls! Long time no see!" You put your arms around them.

"Y/N, who was the boy that just came?" You looked up at the room Tanjiro was staying in. "That's Tanjiro Kamado. He's the boy I told you about the last time I came here." The girls nodded and let you go to the room.

"Hey Tanjiro!" The three boys in the room looked up and saw you. There was a boy with bright yellow hair and another that had a boar mask. "Hey Y/N! Guys, this is the girl I was talking about." You flashed a smile and waved at the two of them. "Hello! My name is Y/N. Nice to meet you!"

The bright yellow haired boy's eyes got wider and wider, and then his head snapped to Tanjiro. "YOU WERE HANGING OUT WITH TWO PRETTY GIRLS?!" Your eyes widened as he shook Tanjiro by the shoulders. "YOU HAVE TO TELL ME YOUR SECRET, YOU'RE ALWAYS MAKING GIRL FRIENDS EVERYWHERE!"

You put your hair behind your ear and turned away. "Anyways... what are your names? Tanjiro has mentioned you, but he didn't say which one's which." Zenitsu grabbed your hand and introduced himself with a slight sparkle in his eye. "I'm Zenitsu Agatsuma, nice to meet you."

You nodded and looked at his arms. "Are they.. supposed to be this size?" You lifted one of his arms rather aggressively and compared it to yours. "It's like.. the size of my forearm." He pulled away. "Some spider demon..." You hummed and looked at the boy with a boar mask.

"Is that the Inosuke you're talking about?" Tanjiro nodded. You tilted your head. "He doesn't seem rash and aggressive like you said in your letter." Tanjiro sat down at one of the beds. "Yeah, he might feel a bit discouraged after the last fight we had."

You nodded. "Did Gi-chan have to help out?" Tanjiro nodded. "And Kocho-sama." You looked at Zenitsu. "So you got poisoned, started turning to some spider child thing, and Shi-san saved you, right?" Zenitsu nodded with a shocked expression. "She has really good intuition."

You sat down in a chair. "Not really. I was able to hear the spider demon talking to you." Zenitsu tilted his head. "I mean, that's my supernatural ability. I can hear things from far away, hear things that already happened, and hear really, really quiet sounds."

Zenitsu put his hand over one of his ears. "My supernatural ability is hearing, too. Just not to that extent." You hummed and got up. "Anyways, I'm helping Kanao and Aoi with your rehabilitation, so I have to get going. See you soon!" You waved and walked out the door.

~Time Skip~

"Hey! Drink your medicine!"

Zenitsu whined. "No...! It's all bitter and gross!" You groaned and picked up the cup. "Do you want to have stubby arms forever?" He shook his head. You gripped him by the top of his head and put the cup at his lips. "Drink." He whined but drank anyways.