Torn from its eccentric orbit around the sun by the dark star Ra, the planet Metalle is a dying world which is slowly drifting into towards a permanent ice age. Only machines can survive in this new environment. The Queen's advisor, the evil Hard Gear, tricks the Queen into pushing the planet's population towards a solution that will guarantee both their survival and immortality. Queen La Andromeda Promescium orders all the population to submit to the process of fully mechanizing the planet and the transformation into the soulless mechanoids. The daughters of Queen Prometheum resist and defy Hard Gear. Hard Gear and his new mechanized army decide that it is not their choice because once he captures Maetel and her fiery twin sister, Emeraldas, he will rule the world. Maetel must choose whether to become a machine to save her life, or to abandon her world to fight for freedom.

Related series are;
Cosmo Warrior Zero
Harlock Saga
Maetel Legend
Queen Emeraldas
Space Pirate Captain Herlock
Arcadia of My Youth