Born on the Blue Star in the Andromeda Galaxy, Blue Cyder came to Earth to protect its peace. By day, she works as a private tutor, teaching her student Koda Izumi, but when villains attack, she transforms into a heroine to fight. Her sense of justice has become a great source of strength for Earth's people, and she lives her daily life as a gentle, composed woman. However, Mukka, the king of the Ape Planet Palnath, an evil force threatening Earth, has devised a plan to eliminate Blue Cyder. His cruel scheme involves kidnapping and brainwashing Masaru, Blue Cyder's beloved student, then using him as bait to trap her.