All Might and his mirror.

Read this before.

Before Shun, and before all his failed successors Toshinori had first attempt at finding a successor. This was during his return to Japan. He didn't really want a successor; he wanted more of a sidekick idea, his own Robin but he changed his idea when Gran Torino talked about a possibility of All For One killing All Might.

Akimitsu Kyohei had been a very good candidate. He was a quiet boy, a very good person from humble origins. His Quirk allowed him to enter mirrors as if they were another dimension.

Akimitsu was like the son Toshinori had always wanted.

They got along very well. Akimitsu was a splendid candidate for One For All, a simple and brave country boy who never stopped smiling. But everything changed when All Might faced All For One in that fight that left them both with mortal wounds.

"He smiled even while being tortured, you know?" All For One held a briefcase.

"What... what are you talking about? Gran Torino? Nighteye? ANSWER ME!" All Might shouted, but thanks to the reaction time granted by One For All, he knew that All For One had thrown something at him... it was Akimitsu's head.

"You're always LATE, Toshinori." All For One yelled as he lunged, intending to kill All Might, who was paralyzed with fear at the sight of the severed head of a young man who only wanted to help.

Although Akimitsu wasn't entirely dead, his own will to see his master smile and continue his heroic ways transformed him into a vestige but different from those of One For All, he's like a ghost, but only All Might can speak and interact with him.

All Might realized this when he saw Akimitsu's in his mirror when he was recovering.

"Sensei! you can do it!" Akimitsu smilled as he looked at All Might

They do talk, though All Might mostly does so when he's alone, and because of this, he has some rather strange mannerisms.

You'll never see All Might in a place with dirty water, for example.

"You know, Sensei... I think the seasons hate me," Akimitsu said, looking at All Might, who was wearing summer clothes and was on vacation in the United States.

"What do you mean?" All Might said, confused, looking at the portable mirror he always carried with him.

"I know autumn hates me because I don't feel nostalgia, and... Summer must hate me with all its being because I'll never feel its warmth again. Spring hates me because I never fall in love... although that was long ago. And winter hates me because I'm much colder than it." Akimitsu made a joke that All Might understood, and it made him spit out ice cream... it was incredible that Akimitsu, even in death and as a kind of ghost, still retained the same sense of humor.

All For One regretted what he did to Akimitsu... the AFO of this universe is nothing more than a brain in a jar with a TTS to talk.

Lots but seriously lots of people think All Might is a metrosexual, or a weird narcissist, because he always carries a portable mirror.