Made in Abyss S01

We step into a world full of caves and enormous holes called Abyss; a place where caves are unexplored, no one knows how deep a cave or hole is, and it is said that mysterious creatures that are unknown to modern humans live in these caves. Over the generations, many adventurers have ventured into the caves, many stories have been formed, and those who have the courage to enter these places are known as "Cave Raiders". In the city of "Orth", which is on the edge of the Abyss region, an orphan boy named "Riko" lives, who wishes to follow in his mother's footsteps, who was once a Cave Raider, and uncover the secrets of these mysterious places. One day, Riko enters a cave and meets a boy... a boy who appears to be a robot...