After biting a vampire in Transylvania, a mosquito finds itself trapped on an airplane bound for Seoul. Then the Transylvanian mosquito bites Na Do-yeol, a corrupt cop in league with a criminal organization. Though Na doesn't become a vampire, he develops a desire for blood causing problems when investigating crime scenes. Additionally, when he becomes aroused by a woman, the vampire in him comes out. Na's criminal contacts threaten his partner and kidnap his girlfriend, and so he embarks on a mission to find and rescue her.