"prevention"yandere demon Slayer x fem reader

friendship

"here, do it like this, straighten your back, go onto the tips of your toes to save energy" Marinette instructed yn, trying to help her learn light breathing.

Yn followed her instructions and Marinette's face brightened, "your so good at this yn, this is definitely the perfect breathing style for you"

yn wasn't as happy about herself being good at this but if marinette was proud of it then she should keep doing it.

Marinette's smile suddenly turned into a smirk, "yn do you want to learn something fun?" she asked yn.

Curious on what this fun thing was yn said yes.

Smiling once more Marinette decided to reveal what the fun this was.

"How about I teach you too sense ghosts?"

Yn stared at the peach haired man blankly, he had a mask on but she could tell he was staring at her, weirdly enough she didn't feel scared like when anyone else stared at her, probably because he was a ghost and not really their.

"How do you.....how do you know I'm a ghost?" Fox dude asked, confusion lacing his voice.

""Let's just say someone I loved a lot taught me how too" yn said.

She and the fox dude fell into silence, before yn decided to break it.

"Help me train" yn said.

"Why do I have to do that! I owe you nothing-"

"Yes you do, I know you looked at me when I was bathing/showering (whatever it is they do in Japan), so repent you perv"

Silence could be heard again, "fine" he sighed out, feeling kind of guilty about being a peeping tom.

And that was the start of their wonderful friendship...

Another six months passed, yn finally managed to remember all of the light breathing forms, lucky for her their were eight of them, two less then water breathing.

The first form was called striking light it's required the user to run towards the target, make it look like their coming for the feet then suddenly the user pushed themselves up and goes for the neck.

The second form is called unexpected light, where the user would suddenly go for his neck from behind.

The third form was yn's favorite, it was called vanishing and reappearing light, where the user runs at the target and when they get to it they suddenly vanish, when in reality their running behind the target and they go for the targets head.

the forth form was called thundering light, it's where the user runs everywhere and attacks random parts of the target before going for the neck.

the 5th form was called castaway light, where the user makes it look like their running away before suddenly coming back to the demons neck.

the sixth form was called piercing light, where the user would come from above and get at the targets neck.

the seventh form was called blinding light, where the user does one strike at the eyes before doing another strike at the neck.

the eighth and final from of light breathing was called everlasting light, it was the hardest to do, the user had to be very fast, it's where the user runs at the target from the front like how they would do in the third form but instead of going behind, they stay at the front and do one simple swing at the neck but if the user isn't fast and strong enough then it wouldn't work. 

the first time yn used the eighth form she nearly broke her arms, so yn put it in the most dangerous to use and only to use when theres no other choice.

fox dude had been a great help, once she had shown him the light breathing forms, he helped yn prefect them, at one point fox dude had told her that he was training tanjiro and he sucked, yn hit him on the head.

right now they were doing a water break, not since yn was hurt but rather because her body was slowing, they were sitting in peace enjoying the nice wind before fox dude said something to break it.

"hey yn since you can't feel pain doesn't that mean you can still feel tickles?" yn stared at him in horror, then she took off desperate to escape the fox dude who was dead set on tickling her until she couldn't breathe...

"Your doing it wrong" yelled fox dude.

"Don't tell me that when I'm the one who knows how to do light breathing! Not you!" Yn yelled back at Fox dude.

Recently they decided to train with tanjiro and fox dudes ghost friend makomo.

He got very pissed when yn called makomo by her real name instead of a Nick name but yn just did that too piss him off so mission complete.

"your still doing it wrong!"

"no i'm not!"

Poor tanjiro and makomo where forced to watch as yn and fox dude argued with each other.

"You need to have a better grip on the ground, your using the tips of your toes! That not right!"

"Yes it is! Marinette told me too do that and she's never wrong!"

"I don't care if that Marinette person told you too, she's wrong!"

Yn was just about to punch him before tanjiro came in between them.

"Hey guys let's no fight, sabito I think we should trust the person who taught yn light breathing okay?" Tanjiro said.

The only answer tanjiro got was a kick in the stomach from fox dude...

a cold breeze could be felt, yn made the mistake of not bringing out any extra clothes to keep herself warm, the feeling of being overly cold wasn't exactly pain but it wasn't a feeling yn liked.

"I told you too bring extra clothes, this is your fault for no listening" fox dude scolded yn.

"Your right it is, but I'm afraid I might freeze do death, do make a fire...please" yn said.

Fox dude shrugged and started to make a fire, once it was up an burning yn relished it's warmth.

She could feel fox dude watching her, he then did something unexpected, he grabbed yn's shoulders and forced her into a hug, where he was hugging yn from behind.

"Hey fox dude, what are you doing?" Yn asked surprisingly not startled by the contact.

"Shut up and let me hug you, idiot"

"Ok you tsundere"

Fox dude hit yn on the head, it was then she decided not to provoke him any longer.

After a while she found herself falling asleep in fox dudes embrace.

The last thing she felt was a kiss on her face.

Ok end.

Taisho secrets~~~~~~~~~~

-tanjiro has been very jealous of sabito since yn has been spending all her time with him

-yn wanted to punch sabito for saying Marinette was wrong

-makomo has never actually said a word to yn, she just stares at her all the time