Jiya is an alien and a galaxy patrol member on a mission to Earth. His first encounter with humankind is rescuing a rich party girl, Kaede, and her chauffeur Kyuumonji Yukio from mountain bandits. Using Kyuumonji's body as a host, Jiya is going to check out rumors of a recent infestation of "vampires" on Earth that are attacking beautiful young women.
Hang Ah was an incarnation of the moon. She was the guardian of the palace since its founding, and her protection resulted in a thousand years of prosperity. But, after a thousand years, she disappeared. All kinds of disasters happened as if it was waiting for this moment of vulnerability. At the same time, a child considered as ‘The Second Hang Ah’ appeared. She wanted to go away believing all of this was a lie. “The Hang Ah I know had beautiful hair resembling the moonlight… Just like you.” ‘I’m… Hang Ah? I can’t believe it…’
Elena, who spent her entire life as a cold-blooded female knight to avenge her family, ended up dying without claiming her revenge. When she opened her eyes she found that she went back into the past. By day she was a lady in a dress, and at night she carried a sword to change history and prevent her family's destruction. "I want to marry you, Your Highness," she said to the crown prince. She would do this to save her family.