The Lore of the Inverted World Chronicle
Three hundred years have passed since the birth of Siegwurm Ira drew the Starhavoc Age to a close. Peace has been maintained by the Zodiac Spirits, who took their names from the constellations above.

However, that tranquility falls into chaos when an inverted landmass suddenly appears one day in the skies overhead. This massive land, which has materialized from another dimension, becomes connected to the earth via a giant snake called Skybinder. It slowly but steadily begins a descent toward the land below.

Envoys possessing a mysterious energy allowing them to take on an Astral form are dispatched from the strange world.

The Zodiacs urgently summon the descendants of the Four Sage Beasts, who soothed Siegwurm Iras rage and restored order to the world. They establish a team of surveyors, whose mission is to uncover the truth about these interdimensional invaders.