Twenty-year-old fashion and art major Una Grimrose rescues an injured bat from a cemetery, unaware he is Azwell, a powerful vampire lord weakened by enemies seeking his court and fortune. After Azwell bites her and makes her part vampire, a charm on her choker seals her powers. Removing it triggers an unknown magical transformation and turns the charm into a silver-stake gun, with future charms combining with the choker’s cross to unlock new weapons. Una remains mostly herself, but now needs blood alongside ordinary food, carried in a creepy-cute tumbler for all to see.