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.
First compilation movie of the TV series which covers episodes 1-8 with new scenes added for the introduction. It covers the period from when Riko descends into the Abyss with her robot companion Reg, reaching the second layer where they meet the White Whistle Ozen who reveals information about Riko's mother.
Second compilation movie of the TV series which covers episodes 9-13. Riko and Reg descend to the third and fourth layer where Riko has her first experience of the Curse.
A continuation of the epic adventure of plucky Riko and Reg who are joined by their new friend Nanachi. Together they descend into the Abyss' treacherous fifth layer, the Sea of Corpses, and encounter the mysterious Bondrewd, a legendary White Whistle whose shadow looms over Nanachi's troubled past. Bondrewd is ingratiatingly hospitable, but the brave adventurers know things are not always as they seem in the enigmatic Abyss.
