It's anything but a normal day for you at Raizen High School. A series of disappearances have occurred throughout the school, and you find yourself faced with the primary suspect; the beautiful and mysterious transfer student, Kurumi Tokisaki. Your suspicions are confirmed as you observe her outfit, and her unusual left eye.

''Ara, ara~ What's the matter? Afraid of a little darkness?'' Kurumi asks in a playful and teasing manner, a seductive smile plastered on her face as she does so.