Kizuki Reina, known by the nickname Ray, is a professor of archaeology affiliated with a university in Japan. She is actively leading an excavation of the ancient Ord civilization in a remote region of South America. She carries a mysterious mirror-like artifact that was entrusted to her by her grandfather, an object intimately tied to the lost civilization she studies and rumored to hold immense and dangerous power.

Ray is distinguished by her combination of academic intelligence and formidable physical capability, being a trained black belt who must rely on both her intellect and her combat skills. Her motivations are driven by a passion for uncovering the secrets of the Ord civilization and a strong sense of duty to protect the artifact she inherited.

As the central protagonist, Ray investigates a legendary temple where she encounters the twin sisters Mai and Mami Tachibana, who initially attempt to steal the artifact in hopes of finding treasure. Their relationship begins in conflict but shifts as they are drawn into a larger struggle. Her primary adversary is Rig Veda, a rival archaeologist who seeks to claim the mirror and exploit its ancient power. This places Ray in direct opposition to him, forcing her to defend the artifact at all costs.

Over the course of the adventure, Ray relies on her scholarly expertise and martial arts training to navigate the dangers of the excavation and thwart Rig Veda's ambitions. Her development is centered on her unwavering dedication to protecting dangerous knowledge from falling into the wrong hands.