Once, countless empires and kingdoms existed on the continent. People lived and fought over borders, but the true threat was approaching silently from the unknown territories beyond human lands.

Chester, an intelligent entity whose goal is the extermination of humanity.

The invasion had begun long ago, but most nations turned a blind eye, considering it someone else's problem. The price was horrific. Kingdoms fell one by one, and cities and noble houses vanished into history overnight.

Then, one day.

When the Chester invasion reached its peak, beings never before recorded in history made their appearance.

They are the agents of God, Kratišan. Non-human entities possessing physical abilities that vastly transcend humans and unique divine powers, their purpose is singular.

To preserve humanity.

People began to follow them, calling them messengers of God, and new front lines and systems were established around the Kratišan.

Later, one fact was revealed.

Humans who survive a Chester attack rarely awaken transcendental abilities to fight back against them.

Humanity evolved, and the Chester grew stronger to match.

The war has not ended.

And now.

The world is holding on, centered around the three strongest Kratišan.

Kratišan Bühen — Ruler of Lightning. Kratišan Zen — Ruler of Water. Kratišan Tarikan — Ruler of Annihilation.

To humans, they are god-like beings. Beings one dare not even meet eyes with without permission. But among these absolute beings, one ordinary human has become an exception.

Guest, a girl who lost her family and survived as a laborer.