Sekai de Ichiban Tadashii Kyuuketsuki no Kaikata

Vampires now coexist with humans, by the terms of their contract with the former anti-vampire organization "Abraham." This contract determines that vampires are to be human's pets, and keeping a pet vampire has become very popular. Their pet collar distinguishes pet vampires from wild vampires, and the wild ones are still quite dangerous. A teenage boy named Daichi really wants a pet vampire, but his older sister won't hear of it. One night, a wild vampire named Iko breaks into his house! The v...