Twelve zodiacs were sent to earth with one purpose: to rule over the earth's four elemental continents.

Everything went well, until the fire and earth signs declared war against the water and air signs. This war was the start of the incident.

Eventually, King Cepheus (the king of all constellations in the sky) declared that the twelve zodiacs were unfit to lead kingdoms, so they were sent to live on the neural continent, while Cepheus created twelve more zodiacs to replace them. These zodiacs were called the imposter zodiacs.

The incident still affected the imposter zodiacs, and resulted in the death of one of the imposter queens

Now the original zodiacs are scattered around the neutral continent, while an unknown thirteenth zodiac tries to bring them all together again.

This thirteenth zodiac was never supposed to be created, but she doesn't intend on letting that stand in her way.