Bnha/mha x little space reader oneshots

Yandere kirishima x reader *i need to keep you safe*

Hello lovely's I hope you like this one. It's been a little bit since I've done a yandere chapter so I decided to do one.
PRONOUNS: they/them ITEMS: stuffie, bottle, pull-ups, onesie TRIGGER WARNING: yandere themes, kidnapping, forced age regression, mentions of cuts/ being hurt (not self harm)
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CONTEXT:
this is a classification AU. You can be classified as a little, caregiver or undefined. You are classified as a little, this can be seen of your wrist but you cover it by always having makeup over it. You work with the red riot agency as a sidekick to red riot. No one knows that you are a little and you plan to keep it that way. Because there is a lot of stereotypes surrounding littles that would prevent you from doing your job anymore if they found out.

Y/n's pov

Today was just a normal day at work, doing some boring paper work in the office, having a lunch break and then the fun part came when me and kirishima were scheduled to go on patrol... but what I didn't know is my day would soon become very not normal.

Me and kirishima and some other hero's work on fighting a villain. This one was pretty big and had some kind of fire quirk, luckily red riots quirk was perfect for defence against that. But I got distracted and in one swift movement the villain launched me across the damn street and into a pond!

"Ow!" I say out loud, I then look down to myself to see if I had any cuts or was bleeding anywhere, then go to get up but before I can I'm pulled up "y/n are you okay?" I hear kirishima ask from behind me as he lifts me out of the sallow water "yeah I think I'm okay... I do have a cut on my wrist though.

He then grabs my wrist before I can say anything... and it's my classification wrist... with the makeup washed off... oh no "... I thought you were undefined? Why does your wrist say little?" He asks sternly "I um... well..." I can't even finish my sentence from how shocked I am. "Y/n tell me the truth are you a little?" I look down at my wrist with little on it and look at kirishima's which readers Caregiver. "Y-yes I am. Please don't tell anyone! "

"Don't worry little one I would never tell anyone... no one will find this out" he said a bit creepily "um you don't have to call me just because I'm a little Kiri..." I say with a frown "aw but I want to... you know I've always wanted a little" he says happily "haha... yeah I know you've talked about it a lot to the point it's an obsession... but I'm not your little" I say I then back away from him because he was starting to scare me. "Where are you going sweetheart?" He asks he then takes a step closer to me "um I need to go home to rest... I'm a bit sore from everything" I say and take a step back away from him again.

Kirishima's pov

Seeing y/n back away from me in fear was upsetting, why can't they just see that now that I know their a little I really want to take care of them? "I don't think so Angel, let's go back to daddies house, where you belong." I then took their hand and pulled them close to me. They let out a gasp and tried to push me away "l-let go kiri! What has gotten into you? You're not my caregiver!" They say angrily, I pull them closer to me and hug them "yes I am sweetie... you're just confused because of how small you feel right now, aren't you? Yes you are~ don't worry when we get home you can be daddy's good little baby!" I say happily, I then pick them up and walk away with them in my arms.

They start to struggle in my arms "no! Kiri listen to me! I'm not your little let me go!" I chuckle at how silly y/n is acting "sweetheart you are... it was destiny that brought you to me... it was a sign you were mine to care for and protect... you poor little baby... having to act all big and strong working along side your strong daddy... I'll never let you work another day in your life" I said happily "now... you should have a nap little one..." I then used a technique I learned in UA to make y/n pass out.

Time skip y/n's pov

I feel so... weird. I slowly open my eyes and see I'm in an unfamiliar room and laying inside of a crib. The room is decorated to look like a nursery... it has (favourite coloured) walls, with a running them of that colour throughout the room. I see a changing table, high chair, rocking chair, a shelve with lots of children books and a toy box. After observing the room I look down to see I've already been changed into a onesie with (favourite animals) on it and now have a pull-up on underneath... {great! I don't even feel little...how am I going to survive this...} I think to myself.

"Aw did the little one wake up already oh! And with such a big frown..." kirishima said in a baby voice "don't talk to me like that! And let me go!" I say annoyedly looking up at him from inside the crib "Aw you have such an adorable angry face! And no... I already told you that I'm now your caregiver so you can't leave... I need to protect you from the dangerous world we live in" he said, he then pinched my cheeks "I am not your little! And just because I am a little doesn't mean I feel little all the time! Give me back my big clothes" I say to him.

Kirishima's pov

I chuckle at y/n's outburst "no no no sweetie, you do feel little, you're just in denial. I can't give you back your big clothes if you're little and why would you want to wear big clothing? Your little clothes look so much more cuter on you" I say and I then pat their head "now no more arguing! Or you may get a punishment understand?" I ask them, they then nodded their head looking away from me "good baby, now let's get you a bottle" I pick them up out of the crib and walk with them in my arms to the kitchen.

When I get there I get out a bottle and prepare to make them a milk bottle "now I'll let you out some vanilla extract or cinnamon in it if you would like baby, since it's your first night with daddy" I say to them, they then chose if they wanted to put anything in it, when they had done that I put the bottle in the microwave to heat it up for them. When it was done I took out the bottle and shake it "alright let's go now" I say, I then picked them back up in one hand and held the bottle in the other.

Y/n's pov

Kirishima carried me back into what I assumed is my new bedroom and sat down in the rocking chair putting me in his lap "now open your mouth so I can feed you your bottle" he said sweetly but I could tell there was force behind what he said. I turned my head away from him, not wanting to have the bottle "y/n... I suggest you do what I say if you don't want to be punished" he said in a threatening tone "and what are you going to do!? I don't care what you do to me I'm not your baby!" I said angrily, crossing my arms and looking away from him.

I feel his grip on me tighten to the point it hurts "oh... I wouldn't say that if I were you, daddy can be very cruel sometimes... it may even affect your family if you don't follow my orders... so be a good little and drink your bottle." He said pushing the bottle to my face...I gave in and started drinking it, he smiled at me and petted my head. "What a good baby you are... just for daddy" he said in a baby voice.

"I love you so much little one~ you'll learn to love me too, especially since we'll be together forever and nothing can change that. Not your family. Not your friends. Not even the hero system can save you from me... no one. You'll always be mine"

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Hello lovely's I hope you enjoyed this, tbh I love writing yandere chapters, I don't know why but I think it might be because of the thrill you get when reading them? If you get what I mean. But I do not condone yandere themes outside of fantasy. Thanks so much for all of your support <3

Love - moon 🌙