The “Abyss” is the last unexplored region, an enormous and treacherous cave system filled with ancient relics and strange creatures. Only the bravest of adventurers can traverse its depths, earning them the nickname, “Cave Raiders.” Within the depths of the Abyss, a girl named Riko stumbles upon a robot who looks like a young boy. Tantalized by the Abyss, Riko and her new friend descend into uncharted territory to unlock its mysteries, but what lies in wait for them in the darkness?
 | Season 1 Episode 1 Town of the Large Hole Air Date: 2017-07-07 Duration: 30 min |
 | Season 1 Episode 2 Resurrection Festival Air Date: 2017-07-14 Duration: 30 min |
 | Season 1 Episode 3 Departure Air Date: 2017-07-21 Duration: 30 min |
 | Season 1 Episode 4 The Edge of the Abyss Air Date: 2017-07-28 Duration: 30 min |
 | Season 1 Episode 5 Incinerator Air Date: 2017-08-04 Duration: 30 min |
 | Season 1 Episode 6 Seeker Camp Air Date: 2017-08-11 Duration: 30 min |
 | Season 1 Episode 7 The Unmovable Sovereign Air Date: 2017-08-18 Duration: 30 min |
 | Season 1 Episode 8 Survival Training Air Date: 2017-08-25 Duration: 30 min |
 | Season 1 Episode 9 The Great Fault Air Date: 2017-09-01 Duration: 30 min |
 | Season 1 Episode 10 Poison and the Curse Air Date: 2017-09-08 Duration: 30 min |
 | Season 1 Episode 11 Nanachi Air Date: 2017-09-15 Duration: 30 min |
 | Season 1 Episode 12 The True Nature of the Curse Air Date: 2017-09-22 Duration: 30 min |
 | Season 1 Episode 13 The Challengers Air Date: 2017-09-29 Duration: 30 min |
| Directing | Masayuki Kojima | Director |
| Directing | Shinya Iino | Assistant Director |
| Sound | Kevin Penkin | Music |
| Directing | Hitoshi Haga | Assistant Director |
| Writing | Hideyuki Kurata | Series Composition |
| Visual Effects | Kazuchika Kise | Character Designer |
| Writing | Akihito Tsukushi | Comic Book |
| Visual Effects | Kou Yoshinari | Creature Design |
| Art | Takeshi Takakura | Prop Designer |
| Sound | Haru Yamada | Sound Director |
| Sound | Toru Noguchi | Sound Effects |
| Art | Osamu Masuyama | Art Direction |
| Editing | Masayuki Kurosawa | Editor |
| Visual Effects | Miyao Miyashita | Color Designer |
| Camera | Tsunetaka Ema | Director of Photography |
| Sound | Miyu Tomita | Theme Song Performance |
| Sound | Mariya Ise | Theme Song Performance |
| Crew | Akihito Tsukushi | Creator |
