Some 400,000,000 years after an advanced human civilization was destroyed by an alliance of planetary conquerers known as Warp Monarch, 12 direct descendants of the civilization's warriors (called Sazers) awaken their powers and join forces with the other members of one their ancestors' four tribes: Flame, Wind, Earth and Water. Each Sazer is based on a Zodiac sign represented in an animal totem or spirit representation. At first, they wage war on each other, but after learning the truth of their ancestry and their reason for awakening, the GranSazer tribes unite to protect Earth from the Warp Monarch from once again extinguishing all life on the planet.

超古代的地球曾经拥有相当高度的文明，但宇宙联盟奥可夫·马纳夫担心人类文明会破坏宇宙的和平，所以出动大军将人类文明彻底消灭。 时至现代，地球上已经筑起了新的文明，但宇宙联盟的威胁亦再次出现。为了人类的未来，凭借超古代文明而觉醒的12位星神战士，将担负起保卫地球……