Zeus, the mighty god of old, established a hierarchy of angels long ago with three tiers: top, middle, and lower. Although they were meant to be equal, this system suggested otherwise. Additionally, Zeus chose six angels as Saint Beasts to govern the creatures of the Earth: Go, the seiyu; Shin, the genbu; Rei, the suzaku; Guy, the byakko; Yuda, the kirin; and Ruka, the hooh. However, Kira, the shooting star, and Maya, the fuga, skipped the selection tests and departed for the Earth. The six angels were diligent in their duties, but they grew suspicious of Zeus due to his tyrannical tendencies.