Knock, knock bitch. let me in

they’re not the same stalker, there’s two (which look similar but they’re not)

Then related? Or two random people that share stalking and similar character design because the author wanted them to be mistaken as the same person for only the audience. If it's the second then that's dumb

I think related the two stalkers meet each other in the raws, it looks like they know each other, at least they are friends but because of how similar they look I’d say they’re probably brothers