AN:

So, I originally planned to have today's fic tomorrow, and vice versa. However, I really struggled to write the one-shot I intended to post today, to the point that I gave up and did this one first. Hopefully I can get it done tomorrow, but if I struggle with it I will have to just scrap it and do something different.

Because I'm writing on such short notice again, this is going to be another short fic. However, despite the short notice I was actually really happy with this. Even with no solid idea whatsoever, I quickly found where I wanted to take it and I really enjoyed writing it.

After having so much fun writing this one, I'm definitely writing more Izu/Eri fluff again.

EDIT: 09/08/2020

This was apart of my 'Seven Day Challenge' collection. Now that the challenge is finished, I decided to move this one-shot here.

"Another one Izu-niichan! Another story!"

If someone had told Izuku three months prior that, very soon, he would be an older brother to a beautiful little 8-year-old girl, he would've scoffed. Or laughed. Or, come to think of it, he probably would've overthought things and ran to his mum in a panic, franticly trying to assess whether he had some long lost sister she had hidden from him.

Things had changed a lot since then. There were the obvious physical changes, such as the plethora of scars from his fight with Overhaul. Then there were the more subtle changes: increased control of his quirk, real on-the-ground experience of how hero team ups work, and a better appreciation of just how much responsibility rest upon his shoulders as a hero.

Of course, the biggest change of all was the little girl kneeling on the bed next to him, shaking him as begged for another story.

Despite being an only child, Izuku had never really wished for a younger sibling, perfectly content with it just being him and his mother. He had not once stopped to consider how different things might be if he did eventually have a younger brother or sister.

Then, out of nowhere, Eri had crashed into his life as randomly as All Might had found him all that time ago. Maybe it was fate. Maybe it was luck. Either way, Eri had served as a light in his life from the day she had arrived.

"Izuuuuuuuuu! Pleassssse! Just one more!"

Amused, Izuku threw the covers off him and sat up. He turned to look Eri in the eye and gave her a stern look. "How many stories have I told you tonight?"

Having gained his attention, Eri sat back and scrunched her face in thought. "Ummmm… three!" She shouted, a large, innocent grin blooming on her face.

Trying not to lose his stern façade as his sister melted his heart, Izuku nodded at her. "That's right. And what did you tell me before?"

"I said, 'one more story'!" She exclaimed.

"But now you're asking me for one more story again. How do I know you won't just ask me for another story?"

At this, she rolled her eyes at him as if the answer were the most obvious thing in the world. "Because, you didn't tell me a real story."

Izuku was a little taken aback by that. "What do you mean, a real story?"

Again, the Eri rolled his eyes at him. Before he could pull her up about her attitude however, she leant forward and put both her hands over his heart. "A real story. From here." She told him with a serious expression, looking directly in his eyes. "Not from up there!" Cracking a smile, she lifted her right hand to poke him in the forehead.

Izuku was momentarily stunned, in awe and pride of the little girl in front of him. She had already suffered more in her short life than most would in their entire lifetime, yet she still greeted every day with a bright smile and an enthusiasm so infectious that it rivalled even the most optimistic of his classmates.

"…Fine." He sighed. Before Eri could start cheering, he gently grabbed her hands and made her look at him. "BUT, this is the LAST ONE. Once I tuck you in, I'll you your story, then we sleep." He put his hand out to her to shake on it. "Deal?"

She quickly grabbed his hand and shook as hard as she could. "Mhmm!" His sister attempted to make a serious face as she nodded, but ended up looking more like she was constipated.

This time he couldn't keep his composure, laughing as he scooped her up into his arms. She squealed in delight as he tickled her, thrashing about so fiercely he almost copped a foot to the nose. Eri might only be eight, but she had a mean kick. He knew that, one day, she would be a powerful hero. Lord have mercy on any poor soul that messed with her and her family.

He stopped tickling her and pulled the covers back, than he laid her down next him before pulling the covers back over them. Finally, he laid back down himself and turned to face Eri as she curled up next to him.

A real story. What could he tell her? Sure he's had some exciting things happen to him over the last two years, but none of it was really child appropriate.

For a moment, he focused on the sound of her breathing. Honestly, how had he gotten so lucky? Whatever higher power had cursed him with Quirklessness and sentenced him to pain and abuse for the first fourteen years of his life clearly had had a change of heart.

From the second he had taken Eri into his arms and escaped from that alley the first day he had met the young girl, she had been attached to him by the hip. Once the police had determined she had no immediate kin, they had tried to place her in foster care. However, every time the police had tried to take her away from him she had fought tooth and nail against it. After a very close call with her Quirk, it was decided that she would take temporary residence with him and his mother.

Inko had been delighted to have another little one around, showering Eri with all the love she could ever want. Inko also made sure to teach Izuku how to properly deal with children, as he was obviously inexperienced.

As time went by, Eri had slowly let her guard down and became less relient on Izuku. Despite her obvious suspicion of most people, she had quickly stolen the hearts of everyone she met, becoming Class 1-A's unofficial little sister.

However, she had spent a lot less time around Izuku in the past month, ever since the creation of the dorms at school. After arguing with the teachers for weeks, they had finally relented and allowed Eri to come for a sleepover for one night only.

A poke to the ribs brought Izuku out of his thoughts. Eri huffed in frustration, pouting at him. "Come on Izuuuu. Story."

Izuku felt himself smile uncontrollably. He wasn't supposed to give positive reinforcement to negative behaviour, yada yada, but he couldn't help it. She was his little sister, and he only got to see her once or twice a week now. He deserved to spoil her.

"Ok, ok. I'll tell you your story."

I meant to actually tell the story, but as I said up top I started writing this last minute. It's 1:40 am at time of writing. However, I really enjoyed this one, and I'll definitely come back and update this one once the challenge is finished.

Review Time:

The Last Cowboy - 'Awww that was wholesome and sweet, really liked it alot. Glad to see some more love for this ship.'

I'm glad there are more MidoTsuyu shippers out there, it definitely needs more attention.

The Last Cowboy - 'I've always enjoyed these more serious topics discussed when it comes to ship fics centered around trauma, and this was really good to read and very enjoyable, I can't wait to see what one shot comes to your mind next. Keep up the good work!'

If you enjoy the more serious fics, stick around for my work after this challenge. One of the fics I have planned will definitely delve into mental health and trauma.

Thank you all for reading, and I hope to see you tomorrow.