actually thats not necessarily true a yandere may be polyamorous seeing as not only is that a life style that is gaining acceptance in modern society with the decline in marriages. but yanderes can be any one from any culture,race, creed or religion so if there are people who are polyamorous then there are yanderes within that group., it all depends on the individual yandere and the setting . there is no hard and fast rule for a yandere except mental instability and obsession.