You are five and Midoriya is six
"This is (F/N), her parent's died in an unfortunate event. I'm sure you heard of it, the car crash near the lake" said the owner of the orphanage as she directs Midoriya and his mom to you.
"Poor girl is still afraid of cars" frowned the owner as she brings Midoriya and his mom to a big playroom full of toys. There you were, a five year old little girl playing with (favourite childhood toy.)
"Mommy we have to adopt her!" cried Midoriya as he tugged onto his mother's dress.
"We'll see" smiled his mom as they followed the owner.
"(F/N)!" called out the owner as she gestures you to go to her. Obeying, you put down the toy and walked over to her.
"(F/N), this is Midoriya-san and her son. They were thinking of adopting someone here" the owner said sweetly as you stared at the boy.
"Uh, hi (F/N)" blushed Midoriya since he doesn't talk to girls very often. Hiding behind the owner, Midoriya's mom crouched down and stuck out a hand.
"Hello (F/N). Would you like to join our family?" she asked sweetly, careful not to frighten you. Nodding your head, you place your tiny little hands onto her soft ones.
"(F/N), go pack your stuff. You'll be leaving tomorrow 'kay sweetie?" smiled the owner as Midoriya saw you race up the stairs with a big wide grin on your face.
The very next day, Midoriya's mom signed the adoption papers as you held a big suitcase full of your clothes, toys and other things that you own. Following your new mom and brother, you watched as you guys were walking towards a car. The memory of your parents instantly began to flood into your mind as you started crying.
"Hey what's wrong (F/N)?" asked Midoriya who was panicking because he doesn't know how to make a girl stop crying. His mom instantly picked you up and started to talk to you.
"You're still afraid of cars? Don't worry we'll make sure you're safe right Izuku?" asked his mom as he nodded along. The whole car ride home was scary, but Midoriya held you tightly to make sure that you were safe.
When you got home, he even helped you up the tiny flight of stairs to make insure that you wouldn't fall. The big brother side of him is finally showing.
The next few years were a bit rough, especially going to school. You were often bullied because you were adopted and it brought you to tears. But, every time someone tries to bully you, Midoriya would come racing in without a care if he gets hurt. He knew he had to protect you at all cost because you were his sister and well, you're a girl and girls aren't supposed to fight.
"Are you alright (F/N)?" he asked as he walked towards you with a black eye. Tears were brought to your eyes to see how he was beaten up by the bullies all because he tried to save you.
"Iz-Izuku! I'm so sorry!" you cried as you apologized to him. He raised his eyebrows and smiled to you.
"Why are you sorry? I'm your big brother! And big brothers are supposed to save the little sister from harm's way!" grinned Midoriya as he held up the victory sign. Shaking your head, you lowered his arm.
"Thank you. Thank you for adopting me, thank you for protecting me and thank you for being the best brother ever!" you shouted as you shut your eyes. Midoriya stood there stunned.
"Therefore to pay to back, I'm going to buy you the biggest All Might figurine there is! And it's going to be signed by All Might himself!" you declared as Midoriya felt the tears coming.
"(F/N), you don't have to do it" said Midoriya but secretly he really did want it.
"No can do Izuku, we made a bond. You did something for me and now it's my turn. You're going to get that figurine no matter what!" you smiled as you stood in a power pose.
This is dedicated @amadingmadi who was the one who requested this chapter. I'm not sure if I completely fulfilled your request correctly but I hope this is what you wanted. This is yet again, another chapter where I vomit out words and hope they all come together and make sense. Request are open and have a nice day/night!