A gunsword-wielding treasure hunter named Ayumi finds herself stuck on a mysterious and dangerous island. While rich with bounty, the island is also caught in the throes of Chaos magic. Ayumi soon discovers that it is also the home of thousands of long-held secrets, including special powers and abilities that she can gain for herself.

Ayumi uses the map to find her way to some ruins. In the heart of the ruins lies an artifact guarded by the Light, a lion-like being, who warns her that the power of the artifact is life-threatening to humans. Ayumi ignores the warning and touches the artifact anyways.