Prompt: YEP! WE ARE DOING SOULMATES, FUCKERS! I'm doing this as I see so many soulmate AUs, but all of them are romantic. I want some family love!
Notes because Soulmate AUs vary:
1. Soulmates are not just romantic. They can be familial or friend-status. I'm stating that here before you bitches assume shit. Soulmates are based on who you will be closet to.
2. Soulmates are determined by a matching mark. Because I am uncreative AF, they will just be shapes or plants (not that this will be important.) The mark glows the other person's hair color if they are using a quirk or when the person is touched by their soulmate. Otherwise, they are just black kind of like a tattoo. Soul marks appear once both of them are alive.
3. Depending on how close they are, it can have different effects. Some can talk to each other through minds. Some have the 'connection.' Some get no benefits because FUCK YOU.
4. There is a noncanon ship here. I have no idea how I am running the story otherwise.
5. This takes place when Izuku is 12, so a little bit after he's starting to drink, but before Shouta is in his life.
6. This is in Shouta's POV so he can JUDGE.
That's everything, so let's go!

Warning: It might be bad. Rephrase, it is.

---

Shouta's POV

I don't know why I bother to sleep anymore.

I was attempting to sleep when Nemuri bursts into the staff room, "Zashi! Sho!"

Hizashi was working, but that 's gone now, "Nem! What's up?"

"Are you two available tonight?"

"Of course!"

"No," I state bluntly. I don't want to get involved in whatever they are planning. Anything involving those two is a mess. It doesn't help that those two are soulmates as siblings/best friends, so it makes the situation worst.

"Sho's is too! He has no patrols tonight! What's up?"

Nemuri smiles, " Well, I want to introduce my soulmate and bestie to my new girlfriend! She's offering dinner tonight, and she wants me to bring over some friends. She loves company, so she would enjoy you two!"

"I don't mind going! Come on, please, Sho?!" Hizashi begs as he gets too close to me.

I sigh, "Fine. When?"

"After we finish our work for school?" Nemuri asks. Hizashi excitably agrees while I reluctantly do so.

Hopefully, the girlfriend is saner than Nemuri.

---

As we near our location, it's now when Nemuri decides to illogically inform us,

"Oh, something I haven't mentioned yet is that she has a son." I can't help but wonder if Nemuri knows what kind of situation she is getting into here. Not only will she be a girlfriend, but she has to mature to become a mother to the kid as well.

Her problem, not mine.

However, that seems to hype Hizashi up, "Really?! How old?"

"He's twelve." That's older than I was expecting. I was expecting a little kid. Not a preteen.

"Really?"

"Yep. He's a good kid, but he is troublesome. I'm just warning you now because there might be some arguing. Or he might not be there at all. It's just who he is."

"Against you? Did you fuck up that relationship already?!"

"No no no! I get along with him great actually. I can't really describe him if I may be honest. You'll know what I mean if you meet him. You'll love him, Zashi. Sho will hate him, though."

"Why? Because he's a kid he would expel?" Hizashi teases. If only they knew.

"Pretty much! Oh, we're here!"

We arrive at a simple apartment compress. After some navigating, we eventually find ourselves in front of a door where Nemuri buzzes in.

When the door opens, it reveals a short plump woman with long green hair and green eyes in typically mother attire.

A bright smile decorates her face as she opens the door further, "Hi, I'm Midoriya Inko. Nice to meet you two. Come on in! And hello Nemuri." Midoriya says as she scurries us in.

Inside the house is surprisingly clean. There isn't a speck of dust anywhere. It's homey but clean in an extreme way. I don't know how it works, but it does.

Nemuri laughs, "You don't have to be so formal with them! That's Yamada, my soulmate who I've talked about, and that's Aizawa. You probably heard a few things about him as well."

Hizashi offers his hand, " Nice to meet you, Midoriya-san!" The two are quick to shake hands, but I don't bother to offer anything. I just want in and out.

Nemuri is quick to notice that, "Don't mind grumpy pants over there. That's just how he is."

Midoriya nods, "That's okay. Please sit down! Would you like anything while I set the table?"

I shake my head as Hizashi replies, "Nah, we can wait!"

Nemuri looks around before facing Midoriya, " Hey Inko, where's Izuku?" That must be the son.

The bright demeanor she had dims a little, "I don't know. He's probably looking for parts again, " Inko faces us, "Izuku is my son. He loves building and programming, so he'll go dumpster diving despite his aversion to it to get supplies. Sometimes he goes overboard with it, so he forgets the time a lot." When Midoriya talks about her son, the light comes back.

Nemuri adds, "He's a genius. I don't know why he bothers with school when he could pass college without a problem."

Hizashi tilts his head in confusion "How smart are we talking?"

"Nezu smart." That catches my attention. If someone is even close to Nezu's intelligence...that's a scary thought.

"Holy shi-smokes! Intelligence quirk?" Midoriya nods to Nemuri, probably expecting her to give the information as she goes to the kitchen to get her plates ready.

Nemuri sighs, "Quirkless. I'm pretty sure he's still in school just to spite somebody there." I haven't heard that word in a while. It's rare, especially in this generation. Most quirkless now are elderly, so to hear a quirkless kid is new. Quirkless are discriminated against heavily not only for being considered weak in society, but also because they are the only people without a soulmate presumably. Hopefully, the kid doesn't mind too much that Nemuri spilled something like that out.

"I shouldn't have assumed, but that's amazing!"

After that conversation, Midoriya invites us in to eat, and I haven't tasted something that good in a while.

Through the multiple interactions with Midoriya, she seems like a pleasant person. At least she can balance out her calmness with Nemuri's insanity.

The experience is surprisingly calm despite having two of the most hyper people at the table.

That's until the middle of dinner when the door opens to reveal a short kid with curly-green hair. When the kid looks up, he has bright green eyes, freckles, and a huge grin. Over his shoulder seems to be a bag of presumably junk.

He starts removing his shoes as he talks, "Mom, I'm home! Oh, and I don't have school next week! Oh, and before you ask, Bakugo was being a meanie, so I kicked his ass again! I promise I didn't break anything this time!"

Midoriya sighs, " Sweetie, we'll talk about it later. Come sit down and eat: we have guests."

"Oh shit, sorry you folks had to hear that! Hi, Nemuri! I didn't know you were coming!"

Nemuri straightens up, surprisingly taking a firm voice, "No cursing, kid. And it was a pop-up decision. Just introduce yourself already."

"Bossy AF. Alright!" The kid approaches the table and suddenly spins around and bows, " Hi! I'm Izuku Midoriya! Just call me Izuku, though! Let me put this tech away, and I'll join!"

Izuku is nothing like his mother. He's hyper to the point he can barely sit still, loud, and doesn't watch his behavior. He doesn't even listen to his Mom or Nemuri when they try to settle him down. Izuku is a kid looking for trouble.

Yet, a gut feeling is telling me that I need to watch him. Not that he is dangerous to others but to himself. I don't understand.

"Izuku, you seriously need to reel back, " Midoriya tells her son. Somehow, Izuku's removal from school got brought up.

"If I reel back, then I'm asking for a punch to the face! It's not like I'm going around starting this shit! In fact, I'm leaving him alone! He's the one facing me!"

"Just because you aren't starting it doesn't mean what you are doing isn't wrong! You need to learn self-control!" I've been watching Izuku, and it looks like he is about to explode. I wonder if Midoriya has taken him to a psychologist. His behavior isn't normal. It wouldn't surprise me if he has a couple of mental problems. None of that behavior is healthy.

Usually, I try to avoid interfering, but once again, that gut feeling is telling me to, "Izuku's aware of what he has done. Telling him to stop isn't going to make him stop. If he's being bullied as implied, Izuku isn't in the wrong. Does he need to learn self-control? Yes, but telling him that isn't going to make him gain any unless he finds a reason to." Everyone looks at me including Izuku.

It's quiet for a moment until Izuku speaks up, " I like this hobo." Hizashi chuckles, having been amused this entire meeting. Meanwhile, Nemuri seems shocked that I'm defending the kid, a kid I wouldn't support I add, while the Mom watches Izuku.

"Don't make me regret it, brat, " I snap at Izuku, but that just seems to catch his interest.

"For someone who has been quiet this whole meal, it seems rather odd that the first thing you say is to defend me. I appreciate that!" The kid isn't wrong. I don't bother to respond, "Anyway, since I seem to be ruining this dinner, I'm going to my room. Please make sure to clean up, and good night!" Izuku takes his plate to the kitchen before going down the hall to presumably his room.

Midoriya sighs, probably stressed from the behavior her son demonstrated, "I'm sorry about him. He's a good kid. He's just....troublesome. Izuku always did what he wanted no matter what."

Nemuri pulls Midoriya into a hug, "It's fine. He'll be fine. There wasn't much we can do."

Hizashi is quick to join, "Yeah! He's a pleasure anyway! You have a good son despite his flaws!"

Midoriya smiles at both of them, "Thank you..."

After that, despite Midoriya's request, we clean up for her.

However, Nemuri takes it as a chance to question me, "So Sho, why did you defend Izuku there? Normally, you would ignore or expel that kind of behavior."

Damn it, " It felt different from him." Nemuri is quiet for a moment as she washes dishes until she brings up a conversation out of nowhere.

"How old is your soulmate? Twelve?" Usually, soulmates don't have a large an age gap unless it's parents and children. Most tend to be pretty close in age. For my soulmate, there is a fifteen-year age gap, "And you're certain that your soul mark hasn't glowed once?"

"What are you trying to get at, Nem?" Soul marks are something that helps signify who your partner is. They can either glow because the partner is using their quirk or if they are being touched by their respective mates. Mine has never glowed, and soulmate doctors have just assumed that my soulmate has a weak quirk or just never bothers to use it.

"Sho, that's not how you normally act with anyone. Izuku is twelve. It would make sense for your mark to have never glowed if he's quirkless."

"Quirkless don't have soulmates. You know this."

"Anything is possible. Look, at least ask the kid to touch you. Izuku might bleach himself afterward because he's germaphobic, but it's possible."

"Do you know his birthday?" If you remember the day your soul mark appeared, you already have your soulmate's birthday. My soulmate's birthday is on July 15. If Izuku's birthday happens to be on that date, there's a possibility he is my soulmate. Otherwise, it isn't worth talking to the kid.

"Ask Inko." Ask his mother, who barely knows me, when her son's birthday is. If it gets Nemuri (and Hizashi later) to shut up, fine.

Quietly, I leave the dishes to Nemuri and enter the dining room to see Midoriya tidying up.

It takes her a moment to notice me, "Oh, hi Aizawa! May I help you?"

"I know this is random, but when is your son's birthday?" Midoriya looks at me strangely, and I can't blame her.

"July 15. Why?" I keep my face blank.

"May I go talk to Izuku for a moment?" Midoriya seems more confused but nods.

"Just be careful. He's probably experimenting now."

I nod as I go to the door and knock.

I receive a curse s a response, "Fuck, come in. Let's get this over with."

I open the door, and the room looks more like a lab than a bedroom. Izuku doesn't seem to realize who he let in as he is typing fast on a laptop wired up to presumably a piece of metal.

"Language, kid, " I say with my dull tone. That makes him stop and face me.

"What're you doing here? Don't you have adult things to talk about?" Izuku grumbles as he stands up from his seat.

"I need you for something."

"You barely know me. What?" Izuku asks warily. I watch him analyze me, looking for new details.

"Give me your hand."

"That's gay." I should have known this wouldn't be easy.

"Izuku, I just need to touch you for a moment. I'll let you clean up immediately after." Izuku considers his options. Suddenly, he raises his hand, back up.

"Get it over with." I appreciate him not being dramatic about it like everything else this evening.

I touch his hand and -

---

I start to wake up, and my first question is what happened?

I feel movement beside me along with a string of curses.

Why is there someone with me?

"Did I finally overdo the sleeping meds- ow, what was that for?!" A smack could be heard.

"Izuku, you can't say things like that." I hate to admit it, but when he said it, I felt my nerves rise.

"Whatever. What am I doing here, and why am I sharing a bed with someone I barely know?"

"You have to wait for Aizawa to wake up first." That's when I feel poking in my stomach.

"Wake up! I wanna know! I know you're awake!" This brat is going to kill me. When I open my eyes and sit up, I see HIzashi, Nemuri, and Midoriya around us. Beside me, Izuku barely stays still as he fidgets like a puppy.

I sigh, "I'm up. What happened?"

Midoriya seems to consider her options for a moment, " I'll let the doctor explain. He should be here any minute."

On cue, a classic looking-doctor comes in, "Hello, how are you two feeling?"

I was expecting to feel horrible because I am in a hospital, but I don't. Instead, "I feel good. Randomly good."

Izuku taps his chin, "I don't feel like I died, so explain."

The doctor holds confusion for a moment due to Izuku's dumb comment, but what he says next shocks both of us,

"Well, you two are soulmates. Because you two didn't have a link before, you both were overwhelmed then knocked out." My soulmate is Izuku, someone who is nothing like me.

"Wait, but I'm quirkless. What the fuck?"

"Congratulations! You two are the first pair of soulmates to have a quirkless involved. We don't know how, but it happened. As you are a new pair, it's up to you two to figure out your connection."

"Familial, " Izuku says that without hesitation, but he isn't wrong. It's hard to tell between a brother or a son, but it's definitely familial. I nod in agreement.

"That was quick. Normally, it takes more time to figure out, but your bond must be powerful. There should be no danger in letting you two free, so I'll get the dismissal papers."

With that, the doctor leaves.

This is going to be interesting.