Your Pov 

Me and Tanjiro were dating for a while already i was in my room waking up becaus eit was morning i saw tanjiro a side of me i stand up carefully for not waking him up i went and put my uniform and my haori and my sword, i went back to my room and i didn't saw tanjiro i just though he Woke up until i felt someone breathing in my neck

Tanjiro:¡¡BOO!!

Y/n:HOLY SH-

You smacked tanjiro in the face because you got scared after you saw who was it you literaly Panic

Y/n:I-im sorry! I did not know it was you!! Im sorry!

Tanjiro:Hey hey hey! Is ok dont be sad! Is ok! Is my Fault for scaring you!

You huged him and him just hugging you back and calming you down a while passed you were talking to tanjiro until your bird Came and said

*im gonna put your bird's name hakime but you can put him however you want ^^*

Hakime:Y/n-sama you have a mission at **** you have a mission at ****

Y/n:oh Hakime thanks for telling me im going ok?

Hakime:Is my pleasure i have to go Y/n-sama

Y/n:Bye bye

Hakime:Bye bye

Hakime left the room were you and tanjiro were leaving tanjiro really really worried because what if something really bad happend to you? He huged you really tight you noticed he was crying

Tanjiro:Please...dont leave Stay please please...

Y/n:Tanjiro i need to go

Tanjiro:B-But what if something happend to you?! What if you dont come back what if you get hurt what if-

Y/n:Tanjiro! Calm down im gonna be fine im a hashira Remember?

Tanjiro:I dont care! Only because your a hashira that Doesnt mean you cant get hurt!

Y/n:im gonna be fine i promise..

Tanjiro:No! 

He shouted leaving you worried you didn't know he was that worried about you you just huged him and calmes him down until he falled asleep...you were like that for a while and you saw him asleep you left him in bed and left the room quietly and went to the mission you saw shinobu and told her you were going to a mission but you Told her something

Y/n:Shinobu whatever you do dont tell tanjiro i left in a mission ok?

Shinobu:Sure Y/n you can leave

Y/n:thanks

Shinobu:Mhm!

You left on the way to your mission for finishing it before tanjiro wakes up...in the place were your mission was you were searching for the demon you found him he was eating a old man like of 89 years "Gross" you though and in a Blink of an eye you killed him you were about to leave until your froze in your spot your felt a really horror thing you did not Wanted to feel...Muzan was with you you quickly were about to grab your sword but you got a hit in the stomach and send outside hitting a tree you coughing blood and hitting the floor you stand up and grab your sword searching for muzan you saw him and he looked scary

Muzan:Well Well who do we got here? Y/n L/n Yorichii's little buddy im gonna kill you 

Y/n:Im gonna Complete Yorichii-Sama Wish...Your not gonna kill me

*i forgot to say it was night*

Muzan:lets see about that

You and Muzan start a Fight 

[[Time Skip cause im Lazy to write all the fight]]

Muzan and you were really injured but you were the most injured one you had blood everywere in your body your mask was the one who was not broken yet you were carefull for your mask not to break because it was related to your brothers and your family and it was the last things you haded from them the sun was risita you were gonna defeat muzan but he got running you were gonna attack him but with one of his tentacles he passed your the side of your stomach not letting you some closer you did not let the tentacle go for him to burn in the sun

Muzan:LET ME GO!!!

Y/n:BURN IN HELL!!

He just riped the tentacle and Run away

Muzan:I WILL DEFEAT YOU NEXT TIME Y/N L/N!!!

Y/n:(shit...i Can't be defeated i promised you i was gonna defeat muzan...I CANT DIE)

You could barely walk so you were walking holding your injured arm full of blood you were about to pass out but you saw the kakushies come to your screaming your name and everything went black were you really gonna die?

In shinobu's nursery

Shinobu's Pov

Y/n Is coming late she haven't come yet i wonder if she Is ok i was gonna walk to the outside and saw the kakushies searching for me and i saw Y/n really really bad injured she haded blood everywere in her hed and she haded fire marks *like Tanjiro's in season 2* did she fight muzan? Or a higher uppermoon because she is really a expert killing demons I better hurry up and heal her she might die

[in Tanjiro's side]

Tanjiro:Guys do you know were Is Y/n at?

Zenistu:i dont know i guess she went on a mission

Inosuke:Yeah N/N went in a mission

Tanjiro:SHE WHAT?!

Zenistu:Hmm? What is that I can Hear the kakushies screaming?

Tanjiro:let's check what's going on (Y/n L/n when you get back here I swear to god your gonna regret it)

The 3 boys went outside and saw almost all kakushies taking something until they heard something they did not wanted to hear

Kakushies:ATTENTION Y/N L/N IS BAD INJURED WE NEED ALL KAKUSHIES WITH SHINOBU-SAMA SHE FIGHTED MUZAN KITBUTSUJI AND GOT BAD INJURED WE NEED ALL KAKISHIES WITH SHINOBU-SAMA NOW

Zenistu:Y-Y/n? What?...

Inosuke:what happend to N/N?

All kakushies went to a room making the 3 boys looked at your body full of blood making them froze...especially tanjiro

Zenistu:Y/N!!!

Inosuke:N/N!!!

Kakushies:BOYS PLEASE LEAVE WE NEED YOU BOYS TO LEAVE

Zenistu and inosuke were gonna leave but saw That Tanjiro did not move Tanjiro ran to were you were but the Kakushies ran to him and pulled him behind

Tanjiro:LEAVE ME LET ME SEE HER LET ME SEE HER!!! PLEASE 

Kakushies:TANJIRO KAMADO PLEASE LEAVE Y/N L/N IS IN OPERATION RIGHT NOW

Tanjiro:I NEED TO SEE HER PLEASE I NEED TO MAKE SURE SHE IS OK!!! PLEASE

Zenistu:TANJIRO COME ON LETS LEAVE

Inosuke:GOMPANCHIRO COME ON LET N/N GET BETTER

Tanjiro:YOU DONT UNDERSTAND I NEED TO SEE HER PLEASE LET ME SEE HER

Inosuke:COME ON WE NEED TO LEAVE

Inosuke grabes tanjiro for him not to go to the room were you were treated bit he was using all his strong to go to the room and make sure you were ok

Tanjiro:INOSUKE GET OFF ME I NEED TO SEE HER!!!

Inosuke:LET SHINOBU DO HER JOB

Zenistu:TANJIRO PLEASE LETS GO

everyone was trying to do that tanjiro dont go were you were because he Is not allowed to enter 

Tanjiro:Y/N!!!

[[in your side]]

Y/n's Pov

I was...in the nursery and saw shinobu start if to treated me but i was passing out i could not resist but i made myself Wake up by hitting me in the stomach shinobu told me to stop but i needed to Wake up i needed to revenge Yorichii's dead Muzan needed to be dead after that...everything went black the only thing i saw was Shinobu with a needle 

Shinobu:(Y/n please..dont die we need you)

[[In Tanjiro's side]]

Everyone was trying to make tanjiro stop of what was he doing even all hashira's was there but tomioka was coming

Tomioka:What happend?! Tanjiro stop!

Tanjiro:I NEED TO SEE Y/N LET OFF OF ME NOW

Tomioka:What happend to Y/n??!!

Rengoku:Lady Y/n Is Bad injured and Tanjiro wants to go in the room!

Tomioka:Tanjiro stop Y/n Is gonna get Better please!

Tanjiro:I NEED TO SEE HER I NEED TO MAKE SURE SHE WONT LEAVE ME SHE MADE A PROMISE THAT SHE WAS NEVER GONNA LEAVE ME PLEASE!!!

[[Flashback]]

Y/n:Tanjiro!

Tanjiro:Yeah?

Y/n:if you catch me i will cuddle with you

Tanjiro:Ok!

Y/n:Bye

Tanjiro:Hey! That Is not fair!

Y/n:I never said there was Rules!

Tanjiro:Y/n! Wait up!

Y/n:Try to catch me!

Tanjiro:Oh yeah? Ok!

You and Tanjiro were running playing tag and he catches you

Tanjiro:Gotcha!

Y/n:Aaww man!

Tanjiro:Hahaha Is ok Cmon you Told me that if i Catch you you were gonna give me cuddles!

Y/n:ok ok Cmon 

You and tanjiro cuddled and tanjiro was about to sleep but he asked you something

Tanjiro:*Yawn*

Y/n:someone Is sleepy

Tanjiro:haha i love you...

Y/n:i love you too..

Tanjiro:Y/n promise me something

Y/n:Yeah?

Tanjiro:promise me your gonna be with me always and you will never leave me

Y/n:i promise i wont leave your side never

Tanjiro:Thank you Y/n..i love you so much...

Y/n:i love you too...

[[End of Flashback]]

Tanjiro:PLEASE LET ME SEE HER PLEASE I NEED TO SEE HER Y/N YOU CANT BREAK THE PROMISE

Tomioka:TANJIRO JUST LET SHINOBU DO HER JOB

Tanjiro:PLEASE Y/N YOU NEED TO KEEP YOUR PROMISE LET ME SEE HER 

[[In your Side]]

You were passed put but you could still hear tanjiro scream your name over and over again you knew you needed to Keep your promise but...you couldn't?

Y/n:(Tanjiro...please wait..i promise im gonna be with you soon..just let me get threw this please..i promise im not gonna break the promise..i promise)