>>50240720
The raw definition of yandere is very flexible, all things considered. I imagine some of them hus would begrudgingly and/or somberly let you be if you were to make it clear their love is, unfortunately (for them), one-sided.
However, some of them might merely end up adjusting their behavior to stalk and observe you from afar, assuming they don't already do so (namely the shrine maidens). 'Keeping an eye out' for you, so to speak; potential youkai attack in the woods? Not anymore. Interested suitors and love interests? No, no. Not on their watch.
The reasoning behind this abnormal behavior could vary from 2hu to 2hu. Perhaps she sees this as her personal responsibility, a testament to how important you are to her, regardless of your now distant relationship. Or maybe, on the inside, she just wants you to eventually realize how good she is to you and come running right back to her arms, where you belong. The way it used to be.
It's selfish, it's rotten, it's depraved—but it's from the heart. In a land where most of the inhabitants are man-eating monsters, these corrosive, addictive feelings might just be motivation enough to make it all worthwhile in the end. For you.