Responses
The first thing that comes to mind is Ore Ga Neko Wo Kaburu No Wo Yameta Riyu but I'm not sure if that's what you're looking for, both plots sound similar!
Link: https://www.mangago.me/read-manga/ore_ga_neko_wo_kaburu_no_wo_yameta_riyu/

Hi y’all pls help me find this bl where the seme has a bad personality so he transfer to a new school and changes his personality to a kind and outgoing person but he has a classmate who doesn’t want to interact w him so he’s doing his best to talk to him until he found out that he is a gay av actor then he confronted the uke then found out it wasn’t the uke but his cousin and also they knew each other in middle school and the uke knew that the seme has an awful personality.