OK KO, Let's be Heroes!//KO x Older Sibling!Reader
A/N: I can't believe this hasn't been written before omg. I had the thought of an older sibling reader to KO rolling around in my head while watching the series and was shocked to find no fanfics with the premise. So I did it myself.
NOTE: The Reader's powers are basically Portgas D. Ace's from One Piece. If you aren't familiar, I've attached a few gifs to give you an idea of what it's like.
Word Count: 2026
"Read More Link" placed due to length.
So I can’t think of a realistic way for Reader to be a biological older sibling to KO considering the timeline of what happened.
Soooooooo…You took on the role of KO’s older sibling, even though you’re not related by blood.
[Insert tragic backstory here] and Carol had found you when you were a young teenager wandering about without a home to go to. When she found that out about you, she couldn’t in good conscience leave you alone, so she…adopted you basically. There wasn’t any paperwork involved so you just unofficially become her second child.
Carol was SHOOK when she found out about your superpower (and that’s putting it lightly, she was freaking out--).
It happened when she failed to light the fire underneath her stove a few days after you came to live with her and KO. Not thinking much about it, you held your finger up and lit the fire yourself. When she turned and saw the small fire burning on the tip of your finger she freaked tf out thinking you were hurt.
A one-hour explanation later, she was now on board as to what power you have: You’re made out of fire and can set other things on fire just by looking at them. You even showed her some of your moves the next day faaaaar away from anything flammable.
Carol encouraged you to become a hero and with her help you eventually did. You became a decently high-ranking hero at a young age, clocking in at level 6.
There were a LOT of companies trying and failing to recruit you, but you chose to stay home with Carol and KO (no Carol is NOT crying-).
KO was quite young when you were “adopted,” being around 3 or 4 at the time. Because of that, he always assumed that you were his older sibling by blood and it wasn’t until one day between ages 6 to 11 that Carol told him the truth.
My boy was shocked, but it didn’t change anything between your dynamic.
In fact, you became even more of an inspiration to him on his path to becoming a hero!
You helped Carol a lot at the fitness dojo until Carol got KO a job at Gar’s, to which Carol also had you hired to keep an eye on KO. Not that she didn’t trust him, she just knew that he could get in over his head sometimes and wanted to have someone be there to protect him.
Talking about Gar’s, Rad and Enid absolutely ADORE you. You’re the unofficial manager appointed by them truly because you are a few levels higher than them.
At first, when they heard they were getting two new coworkers, they didn’t think much of it. You and KO seemed nice enough so they didn’t mind having you around.
It’s not until the Darell robot for the day comes busting into the plaza that their opinion changes.
Just ask KO is about to get absolutely decked by Darell, you zoomed onto the scene in a blaze of fire and punched the bot, setting it on fire while also hitting it with enough force to send it back to Boxmore with KO nestled into your other arm.
“Nobody ever touched my little brother.” You muttered under your breath while wrapping KO into your arms further to soothe him. You walk past a stunned Rad and Enid as you enter the store and get back to work.
That day, Rad and Enid also became your younger siblings. Pestering you with questions like “How did you get so strong?” and “Where did you get that power from?” Considering you’re a year or two older and much stronger you embraced the title with honor.
You actually became a little bit of a local celebrity after working at Gar’s for a while. People, locals really, would occasionally come in a ask to take a picture with you. Abashed, you said yes every time because you really couldn’t say no. Real Magic Skeleton even has a picture of you on his site with a small bio (You blushed so hard when you found out you thought you were gonna explode).
Speaking of which, KO LOVES to flaunt you around and hype you up, much to your embarrassment. He says stuff like, “Look at my cool amazingly strong older sibling!” and “My older sibling could beat up your older sibling!”
KO means well, but he embarrasses the shit out of you.
MAD PROTECTIVE. If Carol is protective then you are on another level entirely. If someone even says something mean about KO it’s on sight. People learned very quickly that you are KO’s older sibling and that you will not hesitate to DIE to protect him (KO prays that it never comes to that).
I could see a rude customer coming in and harassing KO about Cob knows what and you just come up behind them and punch them out of the store. When Mr. Gar confronted you about it, you held your ground and stated proudly what you had done. He was honestly surprised at your resolve and didn’t punish you at all, saying “You should stick up for yourself and the ones you love.”
Lord Boxman even became a little weary about attacking the plaza knowing that you worked there and you are a pretty strong defender. That doesn’t stop him, of course, but he does strategize to combat you better.
Professor Venomous encourages Boxman to capture you and “convert” you to villainy since your power is something that could be very useful to them. You’ve heard people throughout your life make comments about how “villainous” your power is, but you never let it get to your head since you know who you are and that’s all that matters.
Taking. Naps. Together. Seriously, if KO ever doses off during one of his shifts, you’re quick to follow him. You’ll scoop him up into your arms and sit down somewhere in the corner and fall asleep with him. Rad and Enid think it’s absolutely adorable and have several pictures of you two.
Rad and Enid will even join your cuddle pile in the break room when time permits (or when they make the time themselves).
KO will even occasionally crawl into your bed at home and sleep with you there. He says that your bed is more comfortable than his, but you really know he gets lonely sometimes.
Piggyback rides! KO loves to lounge on your shoulders and back and will often hang off of you as he does with Rad.
You’re also just used to the feeling of holding/carrying KO that it sometimes feels weird when you haven’t for a while.
When you met TKO for the first time you kinda panicked like many of the other plaza members. It was an especially stressful time in your life (and probably much more for Carol).
TKO wasn’t that fond of you either which made everything 10x harder to deal with. He didn’t actively dislike you, it was more like he wanted nothing to do with you.
Once KO came out of that initial swap between himself and TKO, you didn’t really think much about it.
When he mentioned some “Shadowy Figure” though you immediately began to do as much research as you could on the guy, you were determined to beat the crap out of this guy (if not kill him-).
Listening to KO cry into your and Carol’s arms blabbering about, “I’m so sorry!” and “I don’t know what he did to me!” You honestly thought this man had touched KO (I know I’m not the only one…right??). It took a lot of coaxing, but you eventually managed to understand what happened when KO told you the full story.
It’s not until Dendy begins to monitor KO and TKO that you start to give his alter much thought. You encourage KO to pursue research into his darker ego, assuming he’s okay with it of course, and offer to be someone he can talk to about it if he isn’t comfortable talking to anyone else about it.
During some of these talks, you open up about yourself a bit to KO to make him feel better and let him know that the negative emotions he feels are normal.
During some of the more intimate conversations, you tell him how you used to hurt people and even kill at times before Carol took you in.
KO doesn’t believe you at first. How could someone so kind and loving have killed in their life? You use that to help you explain that good people do bad things sometimes, but that doesn’t make them a bad person.
You teach him that TKO isn’t something that he should be ashamed of and cage up in the back of his mind, but could instead be someone to rely on in times of need.
He feels a lot better after you tell him all of this.
Hugging and holding KO close to you during nights when he feels really bad about himself. Where he doubts his ability to become a good hero and to be able to harness TKO’s powers.
You’d rock him back in forth in his bed while quietly soothing him over his crying. He asked you not to tell Mommy and you promised him that he had your word.
I could honestly see Reader lying to cover up KO’s tracks. Like KO is caught doing something he absolutely should not be doing and instead of immediately admitting fault, you would come up with some realistic yet unfeasible lie that only works about 50% of the time.
KO loves to spar with you! He learned most of his physical skills from you, stuff like punching, jumping, kicking, and all that fun stuff. You’ve never used your fire powers against him though.
There was one incident where Boxmore accidentally found out what your weakness is, that being water. A Shannon bot had thrown you into the little kiddie pool Rad and Enid had set up before the attack started.
When you jumped out of the pool soaking wet and unable to start a fire, the stupid sibling trio laughed and mocked you. Enid was quick to come in with a kick to Raymond’s head and you soon found your footing.
Boxmore learned that day not to underestimate you as even without your powers you’re still a physically strong hero.
However, it would seem that Boxman and Professor Venomous stored that data about you since some of the bots they send are equipped with water guns. You’ve gotten pretty good at dodging them, so that’s kinda cool.
You do remember one time after KO had gotten a handle over TKO where you had been drenched with a bucket of water and right as you were about to get socked by Raymond, KO had pushed you out of the way and dodged the punch himself.
You had never been more proud of KO than in that moment and you made that known to him after the fight. You ran up to him and cradled him in your arms talking about how proud you were and that he was becoming such a fine hero (that last one got him to blush a little).
Rad and Enid definitely took a picture of this and then proceeded to print out a copy and put it in the break room.
When you and KO found out that your mom was dating Mr. Gar, you both were a little unsure about how you felt. When Rad and Enid asked about it, they asked the two of you together and then asked you separately.
Seeing as you’re the older sibling they thought that you would have had a better idea of how you feel about the whole arrangement and were bummed out when they realized that you really didn’t know how you felt.
After the date you four hosted for Carol and Mr. Gar, both you and KO see how happy Mr. Gar makes your mom and decide that if she’s happy then you’re happy as well.
KO is honestly one of the best younger brothers you could ever ask for. He’s kind and selfless and wants to help others when he can. And in return, you are the best older sibling that KO could ever ask for.
Sorry the format looks off in some places, Tumblr just makes booty juice decisions like limiting the character limit per block to 4096 words...
