As Izuku and Izumi Midoriya grew up, they all but had one desire; to be Heroes just like their parents. However, they also enjoyed living like normal childhood for the time being while still dreaming about the future.
The two played with their big sisters Tatsumaki and Fubuki as well as Katsuki. Hisashi would always have time to take his children to go flying with him when he wasn't on Hero Duty, the days spent soaring across the world were the most magical moments to the Midoriya Twins.
Their father also happened to be a huge manga nerd and he had a whole collection of all sorts of manga from the Pre-Quirk Era. Izuku had taken a liking to the One Piece series, admiring how despite the main characters being pirates, they still did heroic things and fought against evil and corruption. As for Izumi, she enjoyed JoJo's Bizarre Adventure, especially the countless memes it had spawned as well as how clever and creative the characters used their powers.
Hisashi, Inko, Tatsumaki, and Fubuki all kept a close eye on the twins, considering their mysterious never before heard Quirk Factors that had been discovered when they were born. They needed to make sure they didn't hurt anybody or themselves on the day their Quirks finally manifested.
And soon, just a few days after the twins' 4th birthday...it happened.
"Come on, Kaachan! Don't bully him!"
Izuku and Izumi were both defending a boy that Katsuki and a couple of his cronies had been antagonizing. Ever since the ash-blonde had developed his Quirk, [Explosion], he had gotten a major swelled head over it.
"Outta the way, you nerds. We're just showing that Villain who's the boss!"
"He didn't mean to take your favorite swing seat, Kaachan! Don't do this!" Izuku cried as Katsuki scowled.
"If you aren't gonna move outta the way then I'll make you!"
Katsuki and his cronies lunged at the Midoriya Twins, who crossed their arms and waited to be hit...only for nothing to happen as Katsuki was heard grunting as he slammed into some kind of wall.
Opening their eyes, the children saw that Izuku had produced a tall clear barrier that Katsuki and a chubby boy with wings, Tsubasa, had bounced off of. As for the other boy, he had been caught by a spectral purple arm rippling with muscles coming from above Izumi.
The two children gazed at what they had just done in awe, then their minds flashed back to their favorite mangas. Izuku remembered one of the characters from One Piece, Bartolomeo, creating these barriers by crossing his arms while Izumi recognized the arm as belonging to the Stand of Jotaro Kujo; Star Platinum!
The boy the twins had been protecting gazed in awe before running off while Katsuki got up and rubbed his nose, which he had slightly banged when he ran into the wall. He then gazed at the barrier and ghostly arm that the Midoriya Twins had created and his blood-red eyes widened.
"No frickin' way..."
After the news was delivered to Inko and Hisashi, they brought their children to the hospital. Tatsumaki and Fubuki couldn't come because they were still in school. After some tense moments, the doctor came back with the records.
"Well, it seems that the Quirk Factors we discovered from their birth were much more potent than we imagined. Your children can use the powers from works of fiction."
"How is this even possible?" Inko asked as the doctor looked over his notes.
"Well, considering your husbands'...unique biology, we can only theorize that it created a brand new Quirk Factor in your children. Little Izuku's Quirk allows him to use the powers from the One Piece manga series by Eiichiro Oda and Little Izumi's Quirk allows her to use the powers from JoJo's Bizarre Adventure by Hirohiko Araki.
"They always did enjoy the manga volumes I had of those two series...could it be their Quirk Factors synched with the idea of those powers being made manifest in real life?" Hisashi asked as the doctor rubbed his chin.
"It's possible. There are many ways that this phenomenon has occurred. My suggestion is that the kids should read through the mangas in order to get a better grasp of their new gifts. The powers they now wield are quite versatile and powerful. Perhaps even stronger than All-Might himself!"
"And maybe even me..." Hisashi muttered. He had always been living in a world of cardboard, his species' physiology making them practically Gods amongst normal men on Earth. However, if his children had the powers from two of the manga series that had the most insane powers imaginable...maybe the world would be in good hands if they mastered them.
Speaking of Izuku and Izumi, they were both practically bouncing in their seats with excitement at the fact that with the powers they now had, they could more than achieve their shared dream of becoming Heroes just like their parents and godfather Toshinori Yagi AKA All-Might.
For the next few years, Izuku and Izumi trained in harnessing their new Quirks. They read through every single volume of One Piece and JoJo's Bizarre Adventure respectively, soaking up every detail about the powers of the many characters since they too had those powers inside them now.
It was a little more complicated for Izumi, considering just how bizarre and unique every single Stand from JoJo was, and don't even get her started on the sheer versatility of the Spin. However, with enough practice, she was able to get the hang of the Stands, Hamon, and Spin.
As for Izuku, the fact that there were countless Devil Fruits in the One Piece universe was quite the headspin but he remained dutiful and practiced with each and every one of them. Hisashi also personally trained his body physicality-wise in order to use the Six Powers Martial Arts used by CP9. Izuku even taught himself Zoro's Three-Sword Style and Sanji's Black Leg Style just because.
Speaking of Katsuki, when he learned of just how powerful Izuku and Izumi had gotten, he set out to train himself so he could hopefully be strong enough to be on par with them. He definitely didn't find it amusing when Izuku showed that one of the Devil Fruits was basically Katsuki's Quirk but more powerful (The Nitro-Nitro Fruit).
When the twins turned 8, Tatsumaki was finally old enough to go to UA High, the same place her parents and godfather had gone to in order to become Heroes. It was heartbreaking when she had to part with Fubuki and the twins but promised to always come and visit them, a promise she dutifully upheld.
The twins were now 9 years old and were walking home from the grocery store with 'Uncle Toshi'. Toshinori Yagi AKA All-Might, who was pretty much the #1 Pro Hero in the world tied along with Hisashi and Inko, was happy to spend some quality time with his godchildren. Ever since they were born, Toshinori had always been the kids' favorite Hero aside from their parents.
Being the appointed 'Symbol of Peace' made it rather hard for Toshinori to spend time with his friends, who were all but practically his family. However, he managed to make time, especially on holidays and on the children's birthdays. Sorahiko had even teased him about how much of a bleeding heart he was, which he took in relative stride.
However, as he and the kids passed an alleyway, they heard sniffling coming from inside. Before Toshinori could react, Izuku and Izumi had already run into the alley. Cursing internally about just how much those two adorable little gremlins wanted to help others just like him and their parents, he followed after them, buffing up into the signature large and muscular form that he used when he was on Hero Duty.
When he reached where Izuku and Izumi had arrived, Toshinroi saw a boy their age with fluffy black hair that covered one of his eyes, freckles on his cheeks akin to the twins, and scarlet red eyes. Upon looking at him, Toshinori couldn't help but feel like he was Izuku and Izumi's long-lost sibling in a way judging by his looks.
"Hey, why are you all alone and sad?" Izuku asked gently as the boy sniffled before turning to see All-Might there, his eyes widening with hope.
"All-Might! Y-You gotta help my mom! S-She's being held captive by my dad!"
"Where are they?"
The boy dug into his shirt and pulled out a type of map. The kids were a bit confused by it before handing it to All-Might since he was the adult in the area that they trusted the most.
As he looked at the map, Toshinori's eyes widened in shock before narrowing. He knew where this map led. After so many years, they had found HIM.
Quickly speed-dialing Hisashi and Inko, Toshinori put the phone up to his ear.
"Inko, Hisashi, I need you to gather the Top 10 Pro Heroes and as many others that you trust. We found him...ALL FOR ONE."
The boy that Izuku and Izumi had saved, who went by Akatani Mikumo, was now with the twins and Fubuki at the Bakugou household. Katsuki was also there and quite antsy, wanting to see All-Might defeating the Villain that 'Auntie Inko' and 'Uncle Hisashi' had told him was the toughest Villain around.
After many agonizing hours and Tatsumaki coming home from school to make sure that her siblings were alright, Inko and Hisashi came home, looking slightly battered but no worse for wear.
"Momma! Papa!" Izuku, Izumi, and Fubuki all cried as they ran to their parents, Tatsumaki wordlessly rushing alongside them as the four Midoriya children embraced their parents.
"Oh thank god, you're okay!" Mitsuki said in relief as she, Masaru, and Katsuki came over, the young blonde child rushing in to hug his aunt and uncle.
"What happened?" Masaru asked, fret with worry.
"That bastard proved tougher than expected...but we managed to beat him."
Inko noticed Akatani by his lonesome, looking away from his seat on the couch. The kind woman approached the boy and got down on one knee to look him in the eye.
"Sweetie, you're Akatani, right?"
The raven-haired child numbly nodded as Inko hugged him. "Your father won't hurt you anymore...we couldn't find your mother, though."
Akatani sniffled but didn't cry, though tears did leak from his eyes as Inko continued to hug him. Gingerly, he hugged her back.
"Akatani...would you like to live with us?"
And just like that, Akatani Mikumo became Akatani Midoriya, though he still kept his original surname of Mikumo as well, wanting to remember his roots so he could grow stronger from them as he moved towards the future, especially as Izuku and Izumi stood by his side and welcomed him into their family with open arms.
However, something terrible had happened during the battle with Akatani's father, and right now, while the family was there to get his Quirk registered, he was visiting the man who risked his life to stop his monstrous dad...
"I'm sorry..."
Toshinori, who had been in the ICU for the past few days since the battle with his enemy. His stomach had been pulped and one of his lungs had to be removed in order for the resulting surgery to save his life. Akatani was currently visiting him, blaming himself for the Symbol of Peace being in the condition he was currently in.
Toshinori just smiled, he had recovered slightly but he still needed to be bed-ridden for a few more days. He then placed a hand gently on Akatani's head.
"No, I'm sorry. I couldn't find your mother. No doubt your bastard father took her away somewhere before he fought."
"But you still got hurt because you decided to help a Villain's child...I don't know why you don't blame me."
Toshinori chuckled. "I wouldn't be able to call myself a Symbol of Peace if I ignored a child in distress, even if he is the son of my enemy."
Akatani teared up and then hugged Toshinori as gently as he could so as to not hurt him. The blonde man sighed as he hugged the boy back, the rest of the Midoriya Family watching from by the door with smiles on their faces.
"There's a reason Mom passed down her Quirk to you..." Inko said softly as she thought back to her childhood, happily hugging a beautiful woman dressed in a simple but powerful Hero Costume along with her brother...
The man known as All for One was at his lowest point. He coughed weakly as he was strapped to a makeshift ICU bed while his doctor and trusted associate, Dr. Daruma Ujiko, worked to stabilize his condition.
"All-Might and Paragon certainly did a number on you, old friend."
All for One scowled hatefully. "And they took my son from me...The next time I see them, and I know I will...I will destroy everything they love and make them WATCH!"
"Easy there, your face is already beyond repair, we don't need your heart and lungs in the same boat!" Ujiko scolded as he did his best to help his old friend. He then looked at one of the nearby pods and smirked, glad they at least managed to escape with their 'precious cargo'.
As Ujiko was doing his best to heal All for One, a slow chuckle echoed through the laboratory. Looking around, the two men couldn't help but feel a shudder running up their spines before a tall and lanky figure stepped in, a malevolent grin full of filthy yellow teeth flashing through the darkness.
"Well, well, well, can't believe you're in this sorry state, Shiggy. Should I have brought a Get Well Card?"
If All for One still had his eyes, they would be widening in disbelief as he and Ujiko stared at the single man more fearsome than them. A man who had existed for countless years mostly in part due to All for One passing down a copy of Ujiko's Quirk to him but also via sheer tenacity and the desire to simply cause nothing more but pure, unabashed CHAOS.
"So...what say we give this whole stinkin' country a better class of criminals for the future?"
And so the Midoriya Family welcome Akatani Mikumo, son of All for One, into their clan. And an old friend of All for One is making himself known in order to spice up what the League of Villains will have to offer in the future.
The next chapter will be the start of Canon, with the Midoriya Triplets spending their last days at Aldera Junior High before graduation and confronting the Sludge Villain before getting ready for UA High!