Located in the center of a remote island, the Abyss is the last unexplored region, a huge and treacherous fathomless hole inhabited by strange creatures where only the bravest adventurers descend in search of ancient relics. In the upper levels of the Abyss, Riko, a girl who dreams of becoming an explorer, stumbles upon a mysterious little boy.
| Title | Air Date | Duration | ||
|---|---|---|---|---|
| Season 1 | Episode 1 | The City of the Great Pit | 2017-07-07 | 30 min |
| Season 1 | Episode 2 | Resurrection Festival | 2017-07-14 | 30 min |
| Season 1 | Episode 3 | Departure | 2017-07-21 | 30 min |
| Season 1 | Episode 4 | The Edge of the Abyss | 2017-07-28 | 30 min |
| Season 1 | Episode 5 | Incinerator | 2017-08-04 | 30 min |
| Season 1 | Episode 6 | Seeker Camp | 2017-08-11 | 30 min |
| Season 1 | Episode 7 | The Unmovable Sovereign | 2017-08-18 | 30 min |
| Season 1 | Episode 8 | Survival Training | 2017-08-25 | 30 min |
| Season 1 | Episode 9 | The Great Fault | 2017-09-01 | 30 min |
| Season 1 | Episode 10 | Poison and the Curse | 2017-09-08 | 30 min |
| Season 1 | Episode 11 | Nanachi | 2017-09-15 | 30 min |
| Season 1 | Episode 12 | The True Nature of the Curse | 2017-09-22 | 30 min |
| Season 1 | Episode 13 | The Challengers | 2017-09-29 | 30 min |
| Season 2 | Episode 1 | The Compass Pointed to the Darkness | 2022-07-06 | 25 min |
| Season 2 | Episode 2 | Capital of the Unreturned | 2022-07-13 | 25 min |
| Season 2 | Episode 3 | Village of the Hollows | 2022-07-20 | 25 min |
| Season 2 | Episode 4 | Friend | 2022-07-27 | 25 min |
| Season 2 | Episode 5 | Concealment | 2022-08-03 | 25 min |
| Season 2 | Episode 6 | The Luring | 2022-08-10 | 25 min |
| Season 2 | Episode 7 | The Cradle of Desire | 2022-08-17 | 25 min |
| Season 2 | Episode 8 | The Form the Wish Takes | 2022-08-24 | 25 min |
| Season 2 | Episode 9 | The Return | 2022-08-31 | 25 min |
| Season 2 | Episode 10 | All That You Gather | 2022-09-07 | 25 min |
| Season 2 | Episode 11 | Value | 2022-09-14 | 25 min |
| Season 2 | Episode 12 | Gold | 2022-09-28 | 47 min |
| Art | Mizuka Ueda | Art Designer |
| Production | Koichi Watanabe | Executive Producer |
| Production | Hiromichi Uchibayashi | Producer |
| Production | Sho Tanaka | Executive Producer |
| Production | Keisuke Sugawara | Associate Producer |
| Sound | Riko Azuna | Theme Song Performance |
| Sound | MYTH&ROID | Theme Song Performance |
| Production | Daisuke Koma | Executive Producer |
| Production | Mitsuhiro Sakakibara | Executive Producer |
| Art | Takeshi Takakura | Art Designer |
| Sound | Hiromitsu Iijima | Music Producer |
| Art | Satoru Hirayanagi | Art Designer |
| Art | Takumi Sakura | Prop Designer |
| Art | Teru Sekiguchi | Art Direction |
| Visual Effects | Yuka Kuroda | Character Designer |
| Production | Sojiro Arimizu | Producer |
| Production | Chisaki Hirano | Associate Producer |
| Production | Akinobu Goto | Executive Producer |
| Production | Fumihiko Shinozaki | Executive Producer |
| Production | Yusuke Kumamoto | Producer |
| Editing | Kazumi Taniguchi | Online Editor |
| Production | Asuka Yamazaki | Executive Producer |
| Art | Yuichi Takayama | Assistant Director of Photography |
| Production | Nobuhiro Takenaka | Producer |
| Sound | Toshihiro Hayano | Sound Recordist |
| Sound | Haru Yamada | Sound Mixer |
| Production | Noritomo Isogai | Producer |
| Production | Jun Kimura | Producer |
| Editing | Chika Ishii | Online Editor |
| Sound | Kevin Penkin | Conductor |
| Production | Shinpei Yamashita | Producer |
| Sound | Haru Yamada | Sound Director |
| Sound | Kevin Penkin | Original Music Composer |
| Directing | Masayuki Kojima | Series Director |
| Art | Osamu Masuyama | Art Direction |
| Writing | Akihito Tsukushi | Comic Book |
| Editing | Masayuki Kurosawa | Editor |
| Visual Effects | Miyao Yamashita | Color Designer |
| Writing | Hideyuki Kurata | Series Composition |
| Visual Effects | Kazuchika Kise | Character Designer |
| Directing | Hitoshi Haga | Assistant Director |
| Camera | Tsunetaka Ema | Director of Photography |
| Sound | Toru Noguchi | Sound Effects |
