Im really bad a descriptions sorry. After someone had found out deku was all mights successor everything turned upside down. His classmates were jealous except a couple. Others bashed him saying he got in because he was all mights successor. Then he rejected uraraka because he didn't want a relationship and some hated him for that for 'leading her on' or 'not even giving her a chance'. On top of that AFO released footage saying Izuku Midoriya is his son. That was the last straw, he was expelled and forced to give his quirk to mirio. His mom let AFO give see izuku one last time but little did she know AFO would give izuku a quirk that could rival anyone and everyone. Once izuku and AFO had spent a day together inko and izuku packed up their things and left to America.