Denial.
Ignorance.
Two things that everyone began to notice in two specific people at UA.
All Might was weakening, often rushing off after class. Students and teachers alike saw how he coughed up blood into his fist or a tissue, how he barely was seen outside of class. Multiple people saw how he occasionally seemed to be smoking, steam rising from his body after he'd been around for more than an hour, and how he sometimes seemed to be less muscular, less overbearing large. His eyes seemed to become less shadowed and more sunken, his smile less confident and more forced, his hair less intimidating and more messy and wild. How he seemed to avoid fighting or overexerting himself, how he started to avoid appearances in public, how he seemed to always be absent from events or assemblies. How, instead of a muscular, blond, tall man wearing a smile, there always seemed to be a skeletal, skin-and-bones, thin, exhausted, blond man on campus, wearing baggy clothes that matched what All Might had just been seen wearing or would be seen wearing later. How Kyoka Jiro overheard All Might talking about his "time being limited" and being "barely able to hold his form for forty-five minutes" to Recovery Girl, and how Toru Hagakure saw All Mighy "deflate" into the skeletal man. How Izuku Midoriya seemed to know about this other form of All Might's, how Izuku called All Might "Toshinori" or "Toshi", how he constantly ate lunch with All Might in the lounge. How All Might was training Izuku personally, how their Quirks were incredibly similar if not the same, how Katsuki Balugo swore that Izuku had been Quirkless from age four until the day of the UA entrance exam. How All Might was obviously favoring Izuku, how he practically cared for the kid like he was Izuku's dad, how he encouraged Izuku more than anyone, how he called Izuku "my boy" and "my kid" instead of "young Midoriya" more and more often. How All Might had been heard calling Izuku his successor, and how both of them never mentioned what their Quirk actually was in public but called it "One for All" in private. How All Might seemed to defend the "Problem Child" (Izuku) against the other staff at UA, how Izuku somehow had All Might's phone number, how he adored All Might, how he yearned for the hero's approval at any chance, how All Might nearly ripped a man's head off for saying that Izuku shouldn't have made it to such a high ranking in the UA sports festival. How Izuku fanboyed over literally every hero except for Aizawa, his homeroom teacher, and All Might, who he'd been a fan of since before he was three. How All Might was often seen talking to Izuku in his weaker form, how Toshinori ruffled Izuku's hair and scolded him like his own kid, how he worried over the boy every second he wasn't with him. How Izuku's old costume looked so similar to All Might, how Izuku was so close to All Might, how he knew about All Might's weaker form and how he occasionally coughed up blood, but not how often the hero was reduced to a coughing fit and couldn't breathe for a few terrifying seconds.
How Izuku Midoriya was ignorant to the fact that his mentor, his hero, his trainer, his idol, his father, was dying.
How Toshinori Yagi, All Might, was in denial that he was dying, and he hadn't told his kid, his trainee, his successor, his mentee, his legacy, about it.
How Jiro heard from a conversation between Toshinori and Recovery Girl that she thought he might not survive until Izuku's graduation.
And everyone was terrified.
There was an unspoken agreement between every single student and staff member at UA to make sure Izuku and Toshinori didn't find out about what everyone knew. No matter what year, Quirk, class, age, or job someone had, they kept their mouths shut around the two. Students kept watch on the beach that Izuku and Toshinori had been found to have cleaned before the semester had begun and that they used to train on. Teachers slipped Toshinori pain relief meds, and "covered" for him if he ever needed to duck out of class during a particularly painful coughing bout. Those with provisional licenses or who were pro heroes slipped out during free periods or at night to patrol the nearby areas for villains or crime to lessen Toshinori's patrol. Students turned a blind eye to steam curling from All Might, or how he staggered occasionally when he walked. Everyone helped him out as much as possible, from carrying things to holding doors to straight-up tricking him into taking a nap in Recovery Girl's office so she could set up a quick IV to help him recover from all the blood and energy he looses.
It gets to the point where All Might collapses during a class period where Izuku was stuck in Recovery Girl's office with a torn leg muscle. When the hero had reverted to his weaker form, everyone had pitched in to make sure he was okay, comfortable, and Kaminari had even run to Recovery Girl's office to tell her what had happened and to keep Izuku informed; telling him that Toshinori had chosen told them rather than the hero having passed out. They help him when he recovers, encouraging him and telling him that they don't care what he looks like, he's still their hero and the Symbol of Peace who takes care of them anyways, and Toshinori relents after Aizawa convinces him to teach as Toshinori instead of All Might.
Izuku is still oblivious, but obviously is a bit nervous with how Toshinori "told" everyone about his other form. The other students assure him that it was okay and that they wouldn't tell anyone, that their teacher's secret was safe with them.
When Tenya Iida figures out that Toshinori has moved into Inko and Izuku Midoriya's apartment as Izuku's father-figure, the entire student and staff body makes the collective decision to include Inko Midoriya in the situation. She takes it as well as expected, and starts to monitor Toshinori outside of school hours, reporting information daily to Recovery Girl and Principal Nezu. She begins cooking meals rich with as many vitamins and nutrients as she can for Toshinori, to try and help his health stabilize, if not grow stronger. She doesn't question the bloodstains on his coat sleeves or his handkerchiefs or the trashcan of bloody tissues. She doesn't question how he wrote a fucking will and entrusted almost everything he owned to Izuku, and yet he refused to call it his will and merely a "precaution". She watches how he spends more and more time with Izuku, training him, acting as a teacher, a hero, an idol, and especially a father to her son. She watches how Izuku is even more oblivious to his hero's condition, his health, and the hundreds of people monitoring them.
No one questions how Toshinori stops teaching battle, rescue, or combat classes, and instead stays in the classroom. No one says anything when he doesn't take his All Might form at all, except to train with Izuku. No one mentions how he doesn't train anymore, instead coaching as All Might for barely five minutes before Toshinori is sitting and encouraging Izuku from the side. No one asks when he doesn't attend events unless Izuku was performing or taking part in them.
It isn't until Izuku's third year that Toshinori's health really starts to decline even further. A coughing fit causes him to wheeze for nearly an hour afterwards; anything faster than a slow walking pace makes him clutch his chest and spit blood. Blood soaks through his shirts on the left side where his stomach and the lower part of his left lung would be, and Recovery Girl reports that she's forced him to bandage an old wound. All Might is a very rare thing to see, as Toshinori is pale, his cheeks hollow, eyes sunken with his pupils dull, his small muscles even tinier and barely visible, his appetite minimal, and his energy sapped. He sleeps frequently, but always is seen eating lunch and forcing himself to be his old self for Izuku. He watches Izuku's training inside the USJ, how his successor has grown stronger than him, faster, more powerful. He makes it to Izuku's graduation as he struggles to transform to All Might, and he hangs up his costume and retires at Nezu's encouragement. He is seen in a wheelchair as his body begins to die, but his mind and heart refuses to follow
It's heartbreaking to see Izuku become a pro hero, become the number-one-hero in the world, and continue to go to his father for praise and encouragement, even as he still doesn't realize how sick Toshinori is.
Everyone continues to watch over Toshinori, and after Izuku takes down All for One and Tomura Shigaraki, he finally accepts his fate.
Students and teachers send him messages telling him about what they've done the past few years, how they've known from the beginning, how they only wanted him to be happy, and how they love him so much. Toshinori agrees to be admitted to a hospital, but quickly demands to return to the apartment he had lived in with Izuku.
He writes a few letters to his old friends and fellow heroes, and on August 26th, Toshinori Yagi tells Izuku Midoriya how he's always loved him as his son, how proud he is, and how he will always be part of One for All, how this was the day that he had received One for All all those years ago, and how he wanted Izuku to be a hero and to remember him, and he makes Izuku promise to live for him.
Then his last exhale leaves his lungs, his last smile brushing his lips, and Toshinori Yagi finally dies as Izuku Midoriya sobs at his side.
The world honors Toshinori by erecting a statue of his true form in every major city in the world, and marking the day he died as an international holiday known as "Toshinori's Peace". They pay homage to the hero who protected the world through messages, memorials, and everything and anything in between. The beach where Izuku Midoriya and Toshinori Yagi had trained and cleaned became known as Hero Beach, and even the villains refrained from causing trouble for a whole three weeks, causing a zero percent crime rate in the world for the first time in history.
Izuku Midoriya continued to be the number one hero for decades, wearing the blue cape of his father and smiling as he protected the world. He lived his life for his father, and when he grew older and his health began to decline, he found a Quirkless fourteen-year-old girl and trained her to become the next hero and holder of One for All. Izuku continued to teach at UA, and to visit Hero Beach for his entire life, living in the same apartment that Toshinori Yagi had died in.
On the same day that Izuku Midoriya had received One for All from Toshinori Yagi, he smiled one last time, and went to join his father and predecessors as the hearts, souls, and minds of One for All.
Just as before, the world lived on, for Toshinori Yagi, for Izuku Midodiya, for everyone who had ever held the Quirk that allowed the holder to save so many lives and bring peace to the world.
And within One for All's spirit, a father and son smiled as they stood on a beach, looking out over the waves.
AN: Okay, yeah, I know I was supposed to start on my other fics, but I decided to wait until 2019 to start rewriting one or two and continuing the others. Don't yell at me.
I just recently entered the BNHA fandom and fell in love immediately. I finished the three seasons of the anime yesterday and plan to read the manga by New Year's, and to watch the movie as soon as I find a way to. I've already gone through ninety percent of the fics on here, and I've decided to write this at...
2 am. Oops.
I actually cried when I wrote this, as awful as the grammar and everything is. I was trying to get across more emotion and the effect of time passing instead of proper writing. This is supposed to take place sort of between seasons 2 and 3, to take a look at Izuku and Toshinori's relationship, what the other students and staff members notice about them, and Toshinori's health concerns throughout the series.
Let me know if I should add BNHA to my list of fics I should write. Please tell me what you think!