I've always wondered this, because it's not your typical shoujo

Jousei is an adult romance manga. Hana yori dango is set in high school, but I feel like it's kinda a Josei.

wdyt??

I think it's based on a shoujo manga according to wikipedia:

https://en.wikipedia.org/wiki/Boys_Over_Flowers

I have a list of dramas/movies based on josei manga:

https://mydramalist.com/list/45GBGxML

Yeah, what @Kez said. Hana Yori Dango was serialized in Margaret, which is a shojo manga magazine based on its demographic (teenage girls)