Deku's Little Sister (Katsuki Bakugo x OC)

Izuku Midoriya: Origin

"Why are you being so mean?" a small boy questioned as he stood next to a small girl, who was defending a small boy on the ground who was crying behind her. "You're making him cry Kacchan!" the small girl added on as she took a step forward. Her quirk started to manifest before everyone's eyes. The small boy gets in a defensive position, despite the fact he felt he could fall over any second with his shaking legs. "If you keep on hurting him, I-I'll...I'll stop you myself!" he yelled, daring to turn his gaze upon the three boys in front of him. They do nothing but stand there and look at the two kids standing up to them. There is a moment of silence before their quirks manifest as well. 

"Hmm. You wanna pretend to be a hero." the boy, who was Kacchan, chuckled as he punched his fist into his palm, making a small explosion upon imact. "You don't stand a chance without a quirk, Deku." he added to his statement. The other small boy, Deku, leaned back and fright as Kacchan began to smirk even more. All three bullies rushed towards Izuku, fully prepared to beat him up. Without thinking, his sister pushed him out of the way and sending Izuku to the ground. Kacchan was getting ready to stop in his tracks, but his arms had already swung. The small girl covered herself up, ready to take the blows. A few seconds later, the small girl is on the ground completely scuffed up. "Hanako!?" Deku shouts as he runs towards her. 

{A Few Years Later} 

One day long ago in Quig Quig, China, a luminescent baby was born with a unique power. Then, as time passed, the similar phenomena happened all over the world, and soon the majority of the population had obtained superhuman powers—known as "Quirks". Due to that, people were able to pursue heroism as a profession. However, Hanako Midoriya's older brother, Izuku, told her a sad truth. That all men were not created equal. When they were both only four years old, they learned that some people had more power than others.  

"Come on, Hanako!" Izuku yelled, waving at her to hurry up. Hanako watched as he continued running, his red shoe stepping into a puddle. She smiled and ran after him, knowing that such limitations wouldn't hold her twin brother back. If anything, it pushed them both to do better. The two siblings wait at a traffic light, one jumping up and down while the other quietly laughs to themselves. The light finally turns green and they make their way across the street, both with content smiles on their face. Their moment is interrupted by a loud roar. Izuku looks first, followed by Hanako to find out what the commotion was.

Hanako heard several people talking about a villain, piquing her interest. "Everyone, please stand back!" a man shouted across the area. Izuku looked up and immediately smiled. "Is that the hero Backdraft!?" Hanako yelled in surprise as the two of them smiled. "Onee-chan! Look, its...!" she continued, pointing above them. "...Kamui Woods!" they both shouted, bursting with excitement. "You fiendish villain have used your quirk illegally, and this shall not go unpunished!" Kamui declared, launching his quirk. "He's about to use his special move..." Izuku mumbled as Hanako pumped her fist high into the air. "Lacquered Chain Prison!" she announced, watching as Kamui Woods made an attempt to stop the villain's movement. 

However, a large lady comes out of nowhere, sending the villain flying. Hanako and Izuku stared blankly at what just happened as the lady stood up. The woman introduced herself, making herself known as Mt. Lady. Several people start taking pictures as she tells everyone that today is her debut and that the situation can be left up to her. Izuku and Hanako immediately start taking notes about Mt. Lady's Quirk. "So her Quirk is Gigantification. It's pretty cool, don't you think Onee-chan?" Hanako asks while looking up from her notebook. "Yeah, but it doesn't seem very useful since she can't use it in small spaces." Izuku replied. "And she can't control the size she can grow either." Hanako adds. 

"Hey, are you two kids some kind of hero nerds?" A man asked the two siblings as they put their notebooks away. "Well, we do have a passion for observing them. I think it's pretty fun to evaluate their Quirks and their ethic as a hero." Hanako answered with a smile as Izuku laughed, failing to give an adequate response. "I see, and are you two looking to become heroes?" the man replied as the Izuku looked at his clenched fist. They both nod excitedly, fully prepared to talk about their aspirations. "It's good to see kids like you trying to get a head start on your goals! Well, I wish you two the best of luck!" the man laughed as he walked away. "Thanks! We'll do our best!" Izuku yelled with a wave before they continued their walk to school.