Overview:
Overview:
The story follows an orphaned young girl, Riko, who finds and befriends a humanoid robot Reg and descends with it into the titular "Abyss", that leads deep into the Earth, in hopes of finding her mother.
The story follows an orphaned young girl, Riko, who finds and befriends a humanoid robot Reg and descends with it into the titular "Abyss", that leads deep into the Earth, in hopes of finding her mother.