#bio dadmight au

[gentrychild]

in your fic where AM was izuku's bio dad and AM sent him away when inko died, did AM's abandonment save izuku? like was AFO just ready to nuke that house until he saw baby izuku all alone and super easily stolen and raised, or was he going to manufacture some situation where he ended up with izuku anyway? feel free to ignore this ask, i just really love your writing and all the implications!!

Well, AFO wasn't about to nuke that house (he might have nuked the other family members to let Toshi find the nuked house and make him believe his son was dead) but Izuku being taken was always part of the plan. It's just that he probably would have been killed and stuffed somewhere to be paraded around later or turned into a noumu.

What saved Izuku from that fate was both Kyoko abandoning him and AFO having the time to grow slightly attached. It was a way for AFO to steal something that belonged to Toshi and make it his.

[fedzkun]

For the ask game : an au where Izuku is all might son but he have all for one quirk and remind all might of all for one

This is just gonna be like the dadmight in my Top Dog Supervillain fic but bio.

Okay, here’s how Izuku got the All For One Quirk and why he reminds his father All Might of AFO: It all started when Yoichi and the other OFA holders got just a little bit more frustrated than usual with the AFO Vestige haunting their realm and they started cooking up ways to get rid of the pesky parasite. One day, Banjo — looking through Yagi’s eyes —accidentally intruded upon a private and intimate moment, then came back to propose his plan of kicking the extra villain luggage into Yagi’s soon-to-be spawn. Yoichi was about to reject the idea after Nana chewed Banjo out, but Second had already booted off the unwanted AFO vestige, much to the others’ horror.

As a baby, Izuku is always doing grabby hands and “up-up” motions at Yagi, more so than he does to his mother. Inko and Yagi find it cute, unaware that little Izuku is acting upon the strong urge of pulling at his father’s Quirk.

Yagi’s blood pressure had spiked to the point that it was a miracle he was still alive when Izuku took a visiting Gran Torino’s Quirk. Oh yeah, Izuku’s AFO Quirk is ranged because it did things to his genes. Anyway, chasing after a toddler flying around like a jet made for an interesting day, but Inko came to the rescue in the end.

Yagi wondered if the villain All For One had something to do with it but nothing triggered his trusted security measures. He also reasoned that All For One would’ve kidnapped Izuku. Unfortunately, the OFA Vestiges were unable to communicate with him. In any case, Yagi vowed to raise his son right. It was a learning process for him as well, as he quickly learned that forcing Izuku to return Quirks is like pulling out his own teeth + fingernails + toenails one by one.

Noticing that asking his son to suppress his Quirk is causing damage to their relationship (and worrying that this might push Izuku to the clutches of AFO), All Might took Izuku to hospitals and institutions where people who want their Quirks to live on might donate them. This satisfies most of Izuku’s urges.

Izuku doesn’t hate heroes, but he IS a comic villain fan. All Might worries that this might apply to reality as well and always brings up his expectations of Izuku becoming a Pro Hero. Then, Inko reminds All Might that the constant worrying could turn the situation into some kind of self-fulfilling “fall into villainy” prophecy and convinces All Might to simply support Izuku in finding his way.

One day, All Might woke up wide-eyed at three in the morning and announced, “All For One would be soooo damn pissed at the idea that my All-For-One-Quirked son is besting him at everything.” And then he took Izuku Quirk-shopping at Tartarus, somehow with no one else knowing.

[aconstantstateofbladerunner]

Trope: Biological Dadmight

A: Love it. Spend my time combing AO3 for it.

The idea has so much potential in so many different directions. I have multiple bio dad might aus

[aerisleis-fics]

Wingbeat Update!

Chapter 25 is up here!  Or you can read from the beginning here! 

Summary:

Pro Heroes Deku and Duality are twenty seven years old when they finally hit a lead in their case, the case they've been working in conjunction with the police since they were twenty three. Nothing goes as planned during the raid sparked by their lead, and they are sent back in time to when the both of them were fourteen years old. With being sent back in time they are given a second chance - a chance to right the wrongs that they lived through. But... every change that is made to the timeline causes ripples that they cannot foresee.

Chapter 25 Excerpt: 

“Izuku…”

“You really believed I had sided with him, didn’t you?” Izuku’s voice was quiet, but he had to ask. He had to know.

“I didn’t know what to think. You seemed so… sure of yourself. But I didn’t want to believe it.”

Not wanting to wasn’t the same as not believing it, Izuku thought to himself, but choose not to say those words.

[radioactivepeasant]

Fic Prompts: Free Day Thursday

(Related to this time-travel au I came up with a while back)

Nana woke to the sounds of murmuring and beeping. She groaned and slowly opened her eyes before immediately closing them again. Why was it so bright?!

"Soraaaa turn it oooffff!" she croaked.

She heard a gasp, and the clatter of a chair.

"Toshinori! Kotarou! Get in here, she's awake!"

Kotarou?!

Nana's eyes flew open. Sure enough, standing in the doorway of a drab hospital room was a young man a head shorter than Toshinori. He looked so much like his father! There was an uncertainty on his face, like he wasn't sure he should be there.

"...hi," he said.

Nana was speechless. How had he found her again? Had something happened to the family she'd placed him with? When had he gotten so tall?

Toshinori limped past him, supporting himself on a crutch that wasn't quite the right height. "We didn't break our promise, Sensei," he said hastily, "He goes to Inko's school. She connected the dots before we did."

Nana looked around the hospital room. "How...how did?"

"It's okay, Nan," Sorahiko's voice was thick with emotion. "All for One is gone. We got him, once and for all."

[[MORE]]

Nana's eyes filled with tears unbidden. "It's over?" she breathed, "And you and Toshi, you're okay?"

Sorahiko scoffed. "Eh, it's just a slight third degree burn. I'm fine. Junior, on the other hand, just about shattered his fool leg kicking All for One into the stratosphere."

"Worth it," Toshinori answered stubbornly. (He wondered if this was how Izuku used to feel. Tried to keep the melancholy from stealing in over his relief.)

Kotarou fidgeted, looking back and forth between them. "Yagi said you've been hunting the villain who...who killed Dad all these years. Was that why you left me?"

Nana winced as she turned her head in his direction. "He...knew where we lived...threatened you by name...I was...so scared..."

She swallowed hard and raised the bed a little so that she could see him better. "The plan was to leave you there until I'd defeated him, then go back and bring you home. I was...underestimating his agenda. I thought he'd be looking for the battle with me quickly, y'know?"

Nana grimaced. "I thought I'd be back in a month. A year, at most. But he'd gotten strong enough that he didn't feel the need to hang around."

Kotarou looked down. "I...guess that makes sense, cognitively. But I won't say I'm over it," he confessed. "I don't know if I can just forget you not being there for thirteen years. But...I'm, uh, glad you didn't die."

Nana blinked back tears. "Can we start over?" she asked, "The four of us?"

Kotarou fidgeted uncomfortably, but after a few awkward minutes, he nodded. "I'll try."

Inko came to visit the following day. She sat on the bed and braided Nana's hair while trying to explain how they'd managed to get an airstrike called in on AFO's hideaway before he could kill Nana. Finding a way to do that without giving away the time travel was hard.

"You're something else, Slingshot," Nana said with a tired smirk. "You know that, right?"

"I grew into it," Inko answered.

Toshinori stepped out into the hall with Inko after a while, to give Kotarou and Nana privacy again. They had a lot of catching up to do.

Inko sighed and leaned against him.

"One obstacle down, who knows how many left."

She groaned. "This time I'm going with you to America. I want to meet David Shield for myself."

Toshinori smirked. "He'll like you."

Then he sighed. "Okay. Three things fixed. Time to change the Doom Calendar again."

Inko elbowed him. "Pessimist. Cheer up, huh? 11 more years until we get Izuku back. We can make it."

Bonus: 12 years later...

Nana handed vegetables to her daughter-in-law and watched her combine them in a very unexpected way.

"Toshi and I picked this up in Texas," Inko explained. "It's a little spicy, but not so much that the kids won't eat it."

At the counter behind them, Toshinori paused in dicing peppers and snorted. "Izuku will eat anything," he said. "Literally I have seen that kid shove raw horseradish into his mouth and then make gimme hands for more!"

Further discussion was halted by Kotarou opening the back door. He looked pale, and they could hear his wife trying to calm the children outside.

"...hey Mom?" he croaked, "Exactly how attached to those flowerbeds were you?"

The adults hastily reconvened outside. The older Shimura twins, Hitoshi and Hana, were pointing and shrieking at what looked like the aftermath of a localized earthquake. The trail of destruction led back to five year old Tenko, who looked shell-shocked. Behind him, his twin sister Nanako was struggling to keep their baby cousin from toddling into the mess.

Little Izuku clapped his chubby hands, squealing his new favorite word:

"Again! Again!"

[angstandhappiness]

SOFT

Colic is really a terrible thing for babies and parents alike. Very hard to deal with. But here, we have a dad doing his best to cope, and he does a rather fine job of it. These are also actual tactics to help a colicky baby. (this is for all of you over at the Ziggurat that got my brain going about skin-to-skin contact)

Bio Dad Might, baby Izuku

Toshinori can feel his eyelids’ valiant attempts at sticking together, exhaustion sweeping through him with a force so great he can hardly bear to fight it. Izuku squirms in his arms, little breaths puffing out of him as he shows his own signs of exhaustion; makes sense, since he’s been screaming for hours.

“It’s alright little boy, Dad’s here…” Toshinori croaks to the six-month-old on his chest. Toshinori is folded into the couch, his spine lax and done with its daily work, unable and unwilling to hold him up anymore.

It’s currently seven p.m.

Izuku whimpers, his voice hoarse from his wails of discomfort, and when the doctor had diagnosed him with colic, Toshinori (and he knows Inko as well) just didn’t know this is what their lives would look like. Endless hours of rocking in different positions that never seem to help, some only making it worse; massages on Izuku’s little tummy to help move the gas along, bicycling little legs back and forth to hope to bring some comfort; warm baths and cloths and soft fabrics.

Some of it helps. None of it fixes the problem entirely.

Toshinori can hear Inko’s deep breaths from their bedroom, her lack of sleep that was written on her face in dark lines finally prompting Toshinori to tell her to try and get some rest. Late-night feedings and diet changes all to try and help Izuku have run her down, and while Toshinori knows she does all of this gladly for the sake of their little boy, Toshinori will take this shift on his own.

His stomach twists a little as he hears Izuku begin to whine again. ‘Witching hour’ the doctor called it. Evening. The worst time for all of this and while Toshinori is tired, his heart aches for the little body that he holds being in so much pain. Izuku twists and squirms more determinedly in Toshinori’s hold. He is gearing up for another round, it seems.

“Alright little one, let��s try again, shall we?” Toshinori says tiredly, pulling out the next item on his mental list that the doctor said would help.

Skin-to-skin contact had been high on said list, and Toshinori knows Izuku loves this from the way he rubs his face into Inko’s skin every chance he gets, and so he tries to be gentle with the upset baby in his lap as he removes his shirt. He hopes Izuku will like him as much as he does Inko. The doctor had said that smell is so much of what a baby recognizes at this age, and Toshinori knows he is no substitute for the woman he loves, but he’ll give it a try regardless.

“Let’s try something new tonight, my boy. I really hope you like it because I’m running out of options, you little stinker,” Toshinori teases, his voice less lilting than he would like. He just can’t summon the energy. “Come on, down you go.”

After he’s stripped Izuku of his tiny blue onesie, leaving him in only his diaper, Toshinori lowers the boy to his chest, laying him out face down with his little cheek right over his father’s heart. Toshinori lies back, letting the couch envelop him in its softness as he lets Izuku get comfortable, his little legs kicking back and forth as he decides whether this is acceptable or not.

Toshinori isn’t holding his breath, no he is not.

He isn’t sure if he’s imagining it at first when Izuku starts to go still.

Toshinori begins carefully, as if the little person listening to his heartbeat is made of glass, to run his hand up and down Izuku’s back, his soft skin like velvet under Toshinori’s palm. Izuku breathes deep, his green eyes heavily hooded but trying so hard to take in all of his surroundings still, his curiosity about the world never waning for as long as he’s conscious. Knowingly, Toshinori runs the pad of his finger down the bridge of a tiny nose and Izuku blinks, long and languidly. Toshinori does it again and this time his eyes stay closed.

Toshinori’s smile is small but relieved.

“Is this what you wanted, little boy? Just to listen to Dad’s heart?” Toshinori feels a blanket of calm come over him, awash with Izuku’s relief and contentedness. He fights the desire to hug the child to his torso, wanting to squeeze him tight and kiss his fuzzy head of hair. He wouldn’t move from this exact position if the world was ending.

“Mom’s gonna be so glad to hear about this, love. So, so glad…” he trails off. He closes his eyes, feeling Izuku’s warmth and his small breaths evening out into sleep. Toshinori won’t sleep but he will rest his mind, still frayed from the last few hours.

Maybe this will work for a while, he thinks, hope blooming in his chest as his hand continues up and down Izuku’s back. Even if this is a one-and-done deal, he’ll take it. After all, Izuku’s happiness is his number one priority now, no matter the hardship. Toshinori sighs.

“Love you, my boy.”

When Izuku’s little fingers grab at his skin for a fraction of a second, he decides he’ll take that as Izuku saying it back.

[pocketramblr]

A Quirkless Hero Izuku without AM bashing I know is WIMTBAH (What it Means to Be a Hero) by DeusVerve and is finished! We don't even have the MLA because they get taken out early! I too long for a Quirkless Hero Izuku fic with no AM bashing. Maybe even Dadmight. Feral Dadmight who let's Izuku inspire him after OFA burns out and they be feral quirkless heroes together. But that may be a stretch. Hell maybe even have them quirkless & feral with Ragdoll.

you gotta filter dadmight to any quirkless izuku fic to strain out more of the untagged bashing but riiiiiiight ok my dreams include:

- Izuku pulling a “no thanks” and Toshi training him anyway because what a difference having a quirkless hero to look up to would have made for him, and then after Kamino Izuku repeating the “you can be a hero anyway” as Toshinori decides that actually, it’d be hilarious to rub in AfO’s face that he’s still a hero even after he burned up the last quirk AfO really really wanted. 

- Quirkless hero toshi training quirkless izuku (ok technically my NOFA au has this but it’d be cool to see with not-bio-dad-might) and they both use fun shield tech and Toshi doesn’t teach heroics at UA (maybe not a teacher at all, maybe a science teacher that he’s actually good at doing atmospheric phycist toshinori truther that i am-) and Toshi also leads a recovery group for heroes who lose their quirk to AfO and fights to give them the chance to stay in the field

- Quirkless Izuku where Toshinori feels weird about Mirio being his successor (in part because he’s picking up on vibes that Mirio’s only doing it bc Sir asked him to) and is like, swinging back and forth on how involved he is in the training and in the meantime meets Izuku and trains him more and more and is like ‘huh. i think this is what its supposed to feel like actually’ (AND there is NO MIRIO BASHING because the points mirio stanning izuku bashers use ARE THE SAME POINTs izuku stanning mirio bashers use and they both INFURIATE ME the same as All Might Bashers do and also canon was dumb to say ‘uhhh fine ok ofa kills quirked users now i dont have to actually defend the CHARACTER of the sucessor because dna is all you need to be worthy now’ but i’m getting off the subject) but then the Shie Hassaikai shoots Mirio with a quirk eraser after the Chisaki fight and he loses BOTH ofa and permeation and then instead of everyone just going ‘oh man that sucks, guess we just have to wait and hope eri can fix it’ they go ‘welp. time for some quirkless training, why would we all believe in a 6 year old with a complete wildcard of a quirk beyond her control over believing in the student who ALREADY overcame difficult training for his quirk and is USED to making quick decisions in changing direction and strategy when he’s fairily well prepared to try the quirkless hero training now huh. why’d we all buy that quirkist nonsense’ and then ragdoll comes to visit at the cultural festival and is like “HEY i want to do that too, im still working with my team but much less now, i want to step it back up and get into the quirkless hero game!”

anyway thank you for the rec!

[musicfeedsmysoul12]

You know, I’d love for a DadMight AU where Toshinori is bio dad to NOT have the same plot has half the Wrong Boy Who Lived fics.

Gimmie awesome dad Toshinori who encourages his son. Who sees his son’s mind and determination and goes: he can do it.

Give me Dad!Might who lets slip he has a son, whose family wears masks to Galas. Let me have cute child Izuku fanboy.

Give me a good AU.

[achairwithapandaonit]

Hmmmmm for a bnha prompt…how would you feel about bio!Dadmight trying to convince Aizawa to meet his biggest fan, Izuku? (Especially if it’s a point where he hasn’t yet/verse where he never will be given OFA)

this is a really hard prompt for me because even if aizawa's one of my favourite characters getting prompts that involve him make me go sort of insane because of both the fandom's obsession with him and the number of dadzawa fics i've read that have just ended up bashing all might. (absolutely not your or anyone else's fault! i just,,, really am so tired of that man by now) but i will try and make a five headcanons thing for this since it's been in my inbox for a while

1) first thing is that i'm not actually a fan of bio dadmight so i'm so sorry i am pretty much stripping away this au you've given me. the found family aspect of dadmight and the way they met is what draws me to it. maybe they meet and all might wants to give izuku ofa but then when he's about to offer it maybe he makes a split second decision that actually, he thinks this kid can do it without it. or maybe he's slightly more on edge, slightly more suspicious that afo could have survived. either way, for some reason he never mentions ofa but still decides to help izuku train for UA

2) izuku's a fan of a lot of heroes and there are a lot of different ones who focus on the kind of fighting he'd need to go into heroics quirkless, but eraserhead has always been one of his favourites because of how little info there's always been on him. when all might mentions that he's going to be working with the man in the following year izuku can't hold back his enthusiasm at the idea of meeting him

3) so all might hounds aizawa a lot to try and get him to meet izuku. he brings him coffee whenever they meet up to discuss lesson plans and tries to invite him out for walks and shows him pictures of his protegee and c'mon aizawa look at his little face he's so polite. eventually aizawa gives in and agrees to meet all might's supposed love child

4) i'm one of those people who actually? doesn't think aizawa would really give two shits about a quirkless hero? even if izuku idolizes him because of the way he fights, it's not exactly quirkless, and i'm sure aizawa would probably see izuku who is quirkless and only really just started training as a liability as a hero. i don't think he'd encourage him, though i think he'd at the very least be a lot more polite about it and keep that to himself in the fact that his future co-worker has taken him to see his probably kid. he probably thinks it's hopeless though. aizawa is shown to expect a lot out of his students

5) i also don't think this izuku would really idolise aizawa that much? he's definitely a hero he likes, but he's no all might. at this point in his life izuku isn't waiting for anyone to tell him that he can be a hero - all might's already told him that. so he hasn't got much of a reason to be more than a little disheartened if aizawa is a bit dismissive of him. and i imagine that'd just push him harder to prove him wrong

[petrichorparacosm]

I really like Dadmight and Dadzawa, but consider THIS AU:

Stepdad All Might and Stepdad Aiwaza!

Shinsou is Present Mic’s biological child whom the latter didn’t know about until the boy was 12- by which point Hzachi had already married EraserHead.

Mic proceeds to cry and shout about being a dad for a week straight while Aiwaza sorts out paperwork and living arrangements.

It makes sense, doesn’t it? Voice based quirk, unusual eyes...maybe bio mom was a villain, even?

Hitoshi comes to live with them, somehow.

No one at the school realizes that Present Mic and Sensei Aiwaza are married, let alone that they are Shinsou’s parents, until one day Mic runs up and glomps himself into a struggling Shinsou, crying incoherently about how “MY BABY IS SO GREAT! I’M SO PROUD.” and Shinsou just looks at Aiwaza like “Dad help.”

Toshinori and Inko bond over co-parenting Izuku, then end up getting married.

Thus Honorary Father All might becomes Stepdad All Might. He sees this as an absolute win.

Izuku is the ring bearer at their wedding.

Even though everyone insists that there is no way All Might is Izuku’s biological father, Todoroki feels vindicated.

Dad jokes. Also Inko is probably the safest woman in all of Japan both her son and husband would throw down for her.

[gentrychild]

Hi Gentry!

Remember that ask I sent for the last ask game? The one with bio Dadmight and Izuku and Shigaraki swap roles? I wanna write the fic now, but I have no clue which direction I wanna go in.

Should I make AFO kidnap and raise villain Deku?

Or should I make Izuku run away, unofficially adopted by Dadzawa while Dadmight frantically searches for him?

Or should I make Izuku jump off a bridge into a river, only to discover he has a mermaid quirk, so he spends a few years in the Pacific Ocean, living his best life, until he's caught in a fishing net and hauled back to land?

Or should I make him hop on a plane to New York City, and become a world famous singer?

There are so many possibilities, I have a whole Spotify playlist dedicated to this AU.

I know that you have a lot of AUs, so I have to ask: when torn on what to do, how do you decide? Flip a coin? Einee minee miney moe? List of pros and cons? Thanks for the advice!

Write all of them.

[tunafishprincess]

I am not sure if this fit as troupe : bio dad might au

A: Love it. Spend my time combing AO3 for it.

Bio dadmight is good shit.

👏😤

[aconstantstateofbladerunner]

A little late but I just read the new chapter of Dekugate, it was really good! As expected! Something got me curious though, how did the sludge villain incident go? It never crossed my mind before how the events of the first episode went in this bio dadmight au, but now I'm quite curious.

Thanks so much!

The sludge villain incident went a little differently. Izuku was still attacked at random, but the villain recognized him and, not wanting to make All Might even angrier, let him go to find a different ‘disguise.’ All Might then appeared and shifted focus to getting his potentially injured son to safety instead of finding the villain, much to Izuku’s horror. The sludge was the worst thing he’d ever experienced up to that point, and the thought of someone else being subject to that was too much to bare. All Might flew him away, intending to take him home and out of danger, but he ran out of power. Izuku got upset he waited his last bit of strength moving him when he was fine and he could have been catching the villain. All Might argued that another hero would pick up where he left off. But on their walk home, Izuku heard Bakugou’s explosions and ran out from under his dad’s supervision. From there, events played out more or less like canon, with the exception of the one for all talk. All Might did tell him he was proud of him for moving when no one else would, and Izuku did cry from happiness, but on the way home, he couldn’t stop crying. That encounter just proved what everyone in his class said: you need a quirk to be a hero. No amount of stupid bravery would change that. In short, he gave up. He went straight to his room when they got home and didn’t come out the rest of the night. So while he was in there, All Might talked to Inko about potentially giving him One for All.

[aerisleis-fics]

Wingbeat of a Butterfly Update

New Chapter up here! It’s Kamino Ward time! Or read from the beginning here!

“He’s here.”

The report from the team on the Kamino side sent a chill down All Might’s back. That was his signal. He raised a hand slightly, Endeavor and Edgeshot both acknowledged it, aware of the fact that he had to adjust to meet All for One.

He was also afraid to find out how much damage he had done as he appeared to the others. How many were already dead? How badly wounded was the team that had been there? They had been prepared for his appearance but not really able to face him, and Toshinori knew that no matter what.

“The missing teen is with him.”

[ao3feed-izuku-midoriya]

Something Just Like This

something just like this by warptimeandspace

Toshinori Yagi would not be mistaken for All Might in a dark room. His body is smaller where All Might continued to grow following the conclusion of Toshinori's growth spurt and his shoulders are more narrow than All Might's. He's still obviously healthy, obviously active, but in the way an athlete is in comparison to a god. It is the strangest blessing in disguise, that All Might is evolved in a way that Toshinori Yagi is not.

Words: 2748, Chapters: 1/1, Language: English

Series: Part 1 of never grow up

Fandoms: 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia

Rating: General Audiences

Warnings: No Archive Warnings Apply

Categories: F/M, Gen

Characters: Yagi Toshinori | All Might, Midoriya Izuku, Midoriya Inko

Relationships: Midoriya Inko/Yagi Toshinori | All Might, Midoriya Inko & Midoriya Izuku, Midoriya Izuku & Yagi Toshinori | All Might

Additional Tags: Pre Canon, bio-dadmight au, Domestic Fluff, hurt comfort, Canon Injury, let them be a family oh my GOD, Parental Yagi Toshinori | All Might, transformation type quirk OFA, Internalized Quirkism

Read Here: https://archiveofourown.org/works/35634691

[radioactivepeasant]

Fic Prompts: Free Day Thursday

(Directly related to this au idea I had last week)

(This will be done in bulletpoint form)

The main premise is that villains attack UA during third year. One of the villains happens to have a time/space warping quirk that reacts very badly to an experimental generator the Support course was working on. The resulting explosion throws everyone at least a little out of their timeline. Those furthest from the blast relive the last ten minutes. Those nearest, matters of months and years. This, as you might imagine, creates a spiderweb of split timelines. Some collapse harmlessly back into the original after a few minutes. Most don't.

[[MORE]]

One of the most dramatic shifts is because Inko and All Might were both in the immediate vicinity of the blast.

Toshinori wakes up in the middle of a Hero Informatics class, his second year of highschool. He's surrounded by people he hasn't seen in ages, all the same age as his students now, and he panics. His first thought is "Did I die?"

Nobody knows who "Midoriya" is when he asks where his students are, and when he asks about Principal Nedzu, one of the girls looks confused.

"You mean the new teacher?" she asks, "The weird mouse guy?"

Toshinori begins to fear that somehow he's just dreamed the future. Or that this is just a dream. He manages to get sent to the nurse's office, and seeing Recovery Girl as the same age as Nana really throws him for a loop.

While in the nurse's office, Toshinori gets a text from a familiar number that just says "Do you remember? Was it a dream? If this isn't you, just ignore this I guess."

He immediately texts back. "Inko?"

They arrange to meet after school to try to figure out what's going on. Is it some kind of mind-manipulation quirk making them relive parts of their past? Time travel isn't real, right?

Inko meets Toshinori at the UA barrier, in her own highschool uniform. (Some of Toshinori's classmates are confused, thinking "I didn't know Yagi had a sweetheart?")

When they compare notes, they eventually conclude that they have to consider the possibility that they are literally some 27 years or so in the past. It's hard to come to terms with. So many important things haven't happened yet -- or may not happen at all. So many friendships haven't been formed, and it feels like mourning, in a way. Especially for Toshinori, who has Nana back, but knows that by the end of the next year, she'll be gone.

Toshinori is understandably worried about how to proceed. What if this is just temporary? They decide to wait a week and see, and if nothing has gone back to normal after that, they'll make a new plan.

They have two different approaches to the situation: Toshinori worries about the possibility of irrevocably changing the future, even if every fiber of his being wants to save Nana, to take down All for One with the knowledge that he has. What if he erases the futures of people who would've otherwise been heroes? What if he erases Izuku?!

Inko, on the other hand, doesn't really believe in those kinds of scifi situations. She believes that "the future" changes minute to minute, second to second, with every choice people make. And some things happen regardless of the choices people make. Inko is of the opinion that Izuku is one of those inevitabilities, especially given how stubborn he is. She refuses to accept any other possibility.

After a few weeks, Inko wins Toshinori over to her way of thinking, and they begin conspiring to save everyone they can

Sometimes this is an accident, like Inko saving preschooler Shouta Aizawa when he falls into a fountain while trying to pet a cat.

Sometimes it's more proactive, like trying to keep the extended Shimura family alive. Toshinori promised Nana he wouldn't go looking for her son. Inko is bound to no such promise. (It takes some Work, but she ends up influencing Kotarou to join the Hero Public Safety Commission, although that hadn't been at all what she was trying to do)

Nana and Gran Torino know something is up. Toshinori all of a sudden got clingy, and he knows things he shouldn't know. But they can't think of a rational explanation outside of the kid maybe meeting someone with a foresight quirk. All they know for sure is that the Midoriya kid he hangs around with is going to give them both grey hair.

(In which we learn that Izuku came by his villain-magnet tendencies honestly)

Gran Torino ends up convincing Inko to keep a bag of marbles around to use her quirk on in case of emergency. She can make them move very quickly and land with a painful impact if she practices enough.

Somehow, this doesn't stop The Many Adventures of All Might and "Slingshot", as Gran Torino nicknames Inko in a moment of irritation.