They adopted you.

You were busy doing SH (Self-Harm) but Hitoshi Shinso (your brother) noticed, he promised not to tell dad (Shouta Aizawa) nor papa (Hizashi Yamada) but he did…

“Hey kiddo, we need to talk.” Shouta said to you, looking slightly concerned behind his mask

“Yea little listener..” Hizashi said, he was obviously concerned. You’re arms started to hurt more because the cuts were deep and probably infected by now so you winced and they noticed…