Izuku sees DEAD PEOPLE...
It wasn’t just seeing All Might that made Slime san scream. Izuku and he both came into contact with a certain item that fell out of the sky.
A shaky Izuku accepted All Might’s offer but later that night a monstrous figure arrived wanting it’s ‘Note book’ back.
Izuku was a good and honest kid so he willingly returned it… but Izuku had touched it and the page had gotten damaged by explosions… he still had a tiny bit stuck to him from the muck.
It didn’t take long for him to figure out that as long as he kept that scrap on him he could SEE them. The Shinigami going about their duties. He could SEE when their time was counting down and he could SEE the seven ghosts hovering about All Might.
He can’t hear their voices but he CAN see their lips move.
Izuku has anxiety and trust issues so he keeps his mouth shut, his head down, his appetite up and his nose to the grindstone.
It isn’t until he gets the Quirk that he starts hearing their voices…