do i have to read the prequels?

I don't think so becoz you can easily understand. The prequels are about the parents so you can read it if you want to.

I don't think the parents will be a part of the story much. You can probably read it on its own and get the gist.

If you can figure out the relationships or generally don't care about who's byul's uncle or cousin from which uncle, then you are good without the prequel

I think so, but you're someone like me who wanna feel connected to the characters, you have to read the prequel.
Its totally fine without it too :)

if*

You should read LIAI first so that you'd see how Byul was made XD.. jokes aside, you'd get understand why Hyesung hates his mom.. It's a fun read, definitely worth your time.