This is a story that takes place after the events of Machina of the Planet Tree -Planet Ruler-. Corona Megistus is a young girl who comes from a family of gemstone magicians. While out training, a chance encounter causes her to come into contact with the core of the Machina, Arcturus. His appearance is a sign that the peace the world has enjoyed is in danger as the seal on a great evil begins to weaken. With the world in danger, the novice gemstone magician departs on a journey with Arcturus to hone her powers and prevent the return of Nova.