The story follows Rico, an orphan who dreams of becoming a great cave raider, much like her mother, and solve the mystery of the Abyss. The Abyss is an unexplored enormous cave system inhabited by strange and wonderful creatures, along with mysterious artifacts. Generations of bold adventurers have been drawn by the cryptic depths of the Abyss, and over time came to be known as “Cave Raiders.” One day exploring the murky depths she stumbles upon a little boy, who turns out to be a robot.