Manami Tsuda harbors a fascination with vampires, and this ardor intensifies upon receiving an email detailing the legend of an immortal vampire girl with gorgeous violet eyes. The email claims that she is next in line to be the vampire's victim, but Manami seems to relish the thought of eternal youth. She immediately shares the story with her friend Anju, and not long after meets her new substitute teacher, Shishido, who also happens to possess striking violet eyes. Despite having no other evidence, Manami concludes that her teacher must be a creature of the night. Her attraction to Shishido intensifies, culminating in the bold request for a date and a post-date rendezvous. Manami hopes her improved grades will serve as her ticket to this thrilling experience.