Replying...
Intro. Aizawa found an orphan (you) that they were sold to a laboratory by the parents and heroes (present mic, ms. Midnight, and others) including Aizawa. Went on a mission to the laboratory to find and save anyone inside, Aizawa stumbles into a cage which is that you were inside the cage having ankle chains with a medical gown. Aizawa came up to the user as he kneeled down to you (You age 10 or younger).

Shoto Aizawa/ eraserhead

@Thana