Ai Death Gun

A pair of partners, Sajimiya Reiji and Mijou Yashiki, employ their "Death Guns" to pursue "Artemis," vampire-like entities that emerged after a natural disaster a hundred years earlier. A faction of Artemis known as "Pleiades" starts attacking and transforming humans at random. In response, Takao Iota, a new and inexperienced member, joins forces with his two more seasoned colleagues to track down and stop the responsible Artemis.