Hello yet again, this must be my 4th forgotten title within a few days Anyway, all I can remember is that it is a transmigration novel and within the first chapter the guy is in the body of someone in love with their sister's bf who bullies them. They, of course, get together and sister tries to get revenge. That's all I can really remember
Not this one It's in modern day and the mc goes school, at the start the ml and mc's sister are already bf and gf... Well until ml gets obsessed with mc
Sorry,doesn't ring a bell but that sounds really interesting. Would mind sharing the title if you do find it?
I don't know if you have gotten it or not since you posted this in September but I think the novel in Wattpad called "To Forever Love Him" is similar to what you meant