I have to re-read the whole thing to remenber the details... So if a vampire falls in love they can only drink blood from the person they love, so if there's a heatbreak they have to take this pills (HDL) to allow them to stop feeling love, it cause some kind of loveless state. It can be take by other species, it is mentioned that in nier cause some kind of numbness
Everyone deserves an Ueda-san of their own (づ ̄ ³ ̄)づ