A/N I'd recommend you read this on A03 or Quotev or Wattpad because the writing is better since I've re-written some of this. Plus I'm tired of all the scam stuff I get on here :'(

"I thought she seemed like a pretty timid girl."

"Obviously not, she's a real delinquent."

"Gosh, she's only nine, she must have learnt it from someone. You think her parents..?"

"It's probably too many hero movies, a kid was being a little rude and she decided to take things into her own hands."

"That makes sense, she said that boy was lying so…"

"Yeah, his dad's All Might," the teacher laughed, "still, no excuse for giving him a minor concussion."

Katsumi had been sitting sniffling in the school office for what felt like forever. Her hands hurt, though the red cuts and sores on her knuckles had disappeared quickly. Still, her eyes remained red from angry tears still yet to fully dry up. She stared out the window, the sun would be setting soon, but her mum still hadn't come to pick her up. Whether that was a good thing or not, she wasn't sure.

The office ladies kept talking about her, she knew it was about her. Even if her English wasn't all that great she could understand most of it. She knew they were calling her names, that they were disgusted by her, that they thought she was stupid.

Tears threatened to spill again, but the young girl wiped them away before they could fall. How had she messed up so quickly? Mummy would be so mad, what if she told Daddy? Then he would never come to see her again.

That boy, that boy said that… No. He was a liar, and he was making fun of how she spoke. He deserved it, if her friend had been here he would have done worse, he was lucky she only hit him.

No, it wasn't nice to hurt people. She knew that. But…

"You see her face when she was hitting him? Real scary!"

"No? Well, maybe she'll be more a villain rather than a hero then," the lady laughed.

Katsumi hated this. She hated it. She clutched her little hands, pulling at the stupid white dress her mum had forced her to wear, now soiled by dirt and sand from when she had pushed that stupid boy to the ground.

She missed her friend.

At least she could see the sun.

She missed her dad.

"Where is she!?"

Katsumi winced as a familiar shout rang out through the corridor. Hurried footsteps came closer as another voice attempted to calm the other down.

The door swung open.

"Oh for god sake Katsumi, what have you done?"

Katsumi stared down.

The office ladies whispered amongst themselves, staring at the woman who had burst in. Katsumi stared down. She was lucky that the principal came out of her office quickly, bringing her mother inside.

Katsumi was left alone again, she hated it, but it was better than being in that room. She just wished that the walls were a little thicker so that she wouldn't have to hear the muffled voices of her mother and the teacher.

Mum was going to be so mad.

It wasn't long till she heard her name being shouted from inside the room. Tentatively, she slid off the chair and shamefully walked to the office door.

"Katsumi!" Her mother turned to her, eyes wide, "Why did you attack this boy!"

"He… was being mean…"

"Seriously? What is wrong with you?"

"Sorry," the principal interrupted, "could we please use English?"

Her mother scowled and turned to Katsumi again, but before she got a chance to speak Katsumi shouted-

"He said that All Might was his dad!"

Her mother's posture stiffened.

"Is something wrong?" The principal asked.

"Katsumi claims the other student was lying," her mother replied, her voice suddenly missing any emotion.

"Yes, from what I have heard, he was," the principal said dismissively, "We've had a lot of problems with that child lying, but that's hardly an excuse to attack another student. I understand that moving to a new country where you don't fully grasp the language is challenging, and Katsumi is clearly struggling with her emotions. However, her reaction was far too extreme than you would expect from a normal child-"

"Let's go, Katsumi," her mother's voice was cold, already turning away.

"Miss Endo-" The principal's eyes widened as the woman roughly took her daughter's hand.

"I'll handle it," she said curtly. "It won't happen again."

"We still need you to talk to the boy's parents and we really must recommend that Katsumi sees a therapist or-"

"I'll parent my daughter as I see fit," Miss Endo snapped. "Maybe you should teach your students not to lie."

With a tight grip on Katsumi's wrist, her mother dragged the girl out of the school and into the harsh Californian sun. Her eyes were blurry, the threat of a fresh wave of tears flowing back down her face. The brightness stung Katsumi's eyes as they made their way to the car and she had to squeeze them shut, wiping the spilt tears away. Her mother yanked open the passenger door without a word. Katsumi climbed and fumbled with the seatbelt.

Inside the car, her mother sat still, hands clenched on the steering wheel, staring blankly ahead. The silence hung heavy between them.

"Katsumi," her mother finally said, her voice cold and distant. "Forget about it. You have no father."

Katsumi's heart raced as tears welled up in her eyes. "Yes, I do! I do, I do!" she cried, her voice breaking. "I want to see him!"

Her mother's grip tightened on the wheel, knuckles white. "Isn't seeing him on the damn television enough for you, you brat?" she slammed her hands against the dashboard. Katsumi flinched back into her seat. Still, she didn't turn to look at her daughter. "It's more than enough for me! Damn it! I have important meetings, Katsumi! If this ever happens again I swear to god I am not picking you up! You can stay in the school till the police drive you to jail for all I care!"

Katsumi choked on her sobs, trembling as she stared up at her mother, pleading for some sign of warmth. But there was none. This was worse than when her friend would get angry with her.

"You listen to me, Katsumi," her mother said, her voice sharp yet cracked as she glared down at her. "I'm giving you a good life here. You can do whatever you want- any club, any activity, any toy or game, I'll give it to you. But you have to forget about that man."

The little girl shook, nodding ever so slightly.

Her mother exhaled heavily, rubbing her temples, "The sooner you forget, the sooner those nightmares will stop. And then you won't need those pills anymore."

Katsumi swallowed hard, her voice barely a whisper. "But that's not…" she swallowed, "Okay, Mummy."

"Well done," her mother muttered, finally strapping herself in and turning on the engine. "And from now on, we'll speak in English. Your pronunciation is terrible."

"In Engirisu," Katsumi mumbled, her voice small and broken.

Her mother shook her head, eyes fixed on the road ahead.

This story takes place at a slower pace than the source material, focusing on the relationships between characters and exploring more of their day-to-day lives than manga/anime. I feel like MHA missed a lot of opportunities for more school-focused moments, which is why I plan to have a good chunk of it in this.
I follow the manga dialogue as it's the most convenient to look at while writing. I started this randomly and was a bit out of practice with writing but the writing improves with each chapter (I'd hope anyway).
The actual story this fanfic follows is darker than canon as it follows my OC, though there is little canon divergence other than the addition of Katsumi (All Might's daughter) and her plot line. I will put a TW before any chapters with particularly bad content. There are plenty of fluff and happy moments as well.
The main idea this is based on is 'What if All Might had a daughter and what would that mean for her?' not much of an original idea but I haven't read any stories with similar concepts so I can't say if this is an original direction to take it. The main love interest is Midoriya, though it's not the focus.
Anyways, enjoy the story! Watch out for updates every fri evening BST.