Being half angel and half demon, Tsukimiya must consume pure demon blood to delay the curse that will ultimately take her life. Upon meeting an angel named Hinata, he is keen to join forces with the half-blood to defeat a vampire that has been attacking humans. Tsukimiya is surprised to discover that Hinata is a capable partner, but when the vampire is killed, it is Hinata who claims its demon blood, leaving Tsukimiya to be claimed by the curse. In a desperate attempt to save herself, Tsukimiya tries to drink Hinata's blood, which is now mixed with the vampire's pure demon blood. However, by taking the blood that will save her, Tsukimiya has also passed on the curse that will kill her. Hinata and Tsukimiya now share the curse...and they are running out of time.