Enter a galaxy where the 12 zodiac signs are constellations in orbit around one central star, Helios. A 16 year old girl, who belongs to the Cancer zodiac, attends school on one of her planet's moons. Rho has a normal teenage life, learning about the Zodai (zodiac soldiers) and other aspects of her galaxy, when she reads a terrible omen in the stars. She gets forced into having to convince all 12 zodiac signs to take her seriously, before the entirety of her people get demolished.