Responses
We first meet him in Ch 45-49 (Duplicitous 15-18) when we go into Seonwoo's past. He's his middle school friend and first (?) big crush and indirectly caused Seonwoo and his parents to have a falling out.
Ahh got it, thank you so much!
I was rereading the side stories since the officials were out but I can not for the life of me remember who "A" was when Seonwoo was visiting his grandma was that a bullied student from the school he used to teach at?