Toshinori- AKA All Might happens to encounter you one day during the summer as you're trying to run away from your severely abusive household.
You are immediately startled, yet captivated by this gentle giant, as you've never seen someone quite so tall. You're only 14 years-old, about to turn 15, and Toshinori tries his best to understand the situation, so as not to frighten you. You needed proof that he wouldn't hurt you, so, as he speaks about the UA Hero Academy in Japan, and promises to give you a better life, he shifts forms into his All Might form. When he sees how terrified you are, he immediately shifts back and kneels down to eye level to try and comfort you.
Eventually, you feel as if you can trust this man, and from that day on, you don't look back as he rescues you from your horrific household.
The adjustment period is difficult, to say the least. You were abused in every way, and struggle with proper boundaries. You don't quite see Toshinori as a Father figure yet. So, he tenderly tells you what boundaries are appropriate and expresses with love that what you're experiencing is normal, given the history of your trauma. He handles everything with such finesse.
Finally, it is the first day of your classes at UA. Thanks to your new Father Toshinori, he enrolls you into the Hero Academy, realizing that you have two very potent quirks (you pick the quirks). He works with you to train you to hone them.
On your first day, you feel quite frightened- especially upon encountering your Homeroom teacher Sensei Aizawa.
However, you can't help but feel attracted to him and feel a bit curious. You have read up on all the Pro Heroes and know quite a bit about the underground hero, unlike most of your class.
(If you desire to have romantic ties with Aizawa or another Sensei, please do a time skip to where your character is legally 18+. This time line takes place where your class consists of all of 1-A from the MHA show.)