It's pretty obvious that whoever got bitten and will come back shouldn't have at least faint need of attachment to a place, Nao, son, husband, mother-in-law and father-in-law were townfolk.
What's grim, Nao by order of Sunako got bitten and she tried to kill/turn all her beloved family who accepted her even though she came from "bad family" one by one without success... Sunako is one evil bitch.
Seishin seems off, he probably won't join the vampire hunt...
Yeah gonna be hard to convince villagers to do a vampire hunt after the ol' bat being too weird...