Dr. Amami is a tireless scientist working in the field of alternative energy, who, at the beginning of the series is on the verge of a major breakthrough in the area of Rynax energy. On her twelveth birthday, his daughter Kurau accompanies her father to the lab, where an experiment goes horribly wrong and she is struck by a bolt of this energy, which knocks her out. When she wakes up again, it is found that her body has been taken over by the Rynaxes, who are actually living organisms, not just a form of energy. One of them is too weak to awaken for ten years, which it eventually does by spawning an identical twin of Kurau, only having the body of a twelve year-old. These two people look and interact very much like two sisters.