Green Relations

Mirai Sasaki never accepted Midoriya as All Might's successor, and the next person to hold One For All. He thought the boy was too reckless. He tried to persuade All Might to choose Mirio, but when that didn't work, he took matters into his own hands, and offered the first year a spot in his agency for work studies. Mirai wanted the boy to give up the quirk, and give it to Mirio, it was that simple of a plan.

What Mirai didn't take into account was discovering the younger boy's horrifying past, and learn his connection to One For All, and how terrifyingly smart he is, also didn't mean for his third year intern to find out the exact reason on why he was chosen to work in his agency (after a whole lot of angst, hugs and tears...because it's Midoriya, come on).

Or,

Nighteye was an asshole in cannon, I'm taking that, putting it in the first chapter and throwing it out the window. I wanted Nighteye to find out about what society did to the green bean, and adopt him...WAIT THAT WASN'T IN THE SCRIPT! Oh- too late I guess. All Might square up, your number one adult fanboy will throw hands for your number one kid fanboy (read: his illegitimate son- fight me on that, I dare you).