Gelegen in het midden van een afgelegen eiland, is de Abyss het laatste onontdekte gebied, een enorm en verraderlijk peilloos gat bewoond door vreemde wezens waar alleen de dapperste avonturiers afdalen op zoek naar oude relikwieën. In de bovenste verdiepingen van de Abyss komt Riko, een meisje dat ervan droomt ontdekkingsreiziger te worden, een mysterieus jongetje tegen.
| Sound | MYTH&ROID | Theme Song Performance |
| Sound | Riko Azuna | Theme Song Performance |
| Production | 田中翔 | Executive Producer |
| Production | 内林大道 | Producer |
| Production | 渡邊耕一 | Executive Producer |
| Art | 上田瑞香 | Art Designer |
| Production | 菅原啓介 | Associate Producer |
| Production | 高麗大助 | Executive Producer |
| Production | 榊原光広 | Executive Producer |
| Art | 平柳悟 | Art Designer |
| Production | 有水宗治郎 | Producer |
| Production | 平野千咲 | Associate Producer |
| Production | 後藤 明信 | Executive Producer |
| Production | 篠崎文彦 | Executive Producer |
| Production | 隈元優介 | Producer |
| Editing | 谷口和己 | Online Editor |
| Production | 山崎明日香 | Executive Producer |
| Art | 高山祐一 | Assistant Director of Photography |
| Sound | 若林豪 | Music Producer |
| Art | 高倉武史 | Art Designer |
| Sound | 飯島弘光 | Music Producer |
| Art | 沙倉拓実 | Prop Designer |
| Art | 関口輝 | Art Direction |
| Visual Effects | 黒田結花 | Character Designer |
| Sound | 野口透 | Sound Effects |
| Camera | 江間常高 | Director of Photography |
| Directing | 垪和等 | Assistant Director |
| Sound | 山田陽 | Sound Mixer |
| Visual Effects | 黄瀬和哉 | Character Designer |
| Writing | 倉田英之 | Series Composition |
| Visual Effects | Miyao Yamashita | Color Designer |
| Editing | 黒澤雅之 | Editor |
| Writing | つくしあきひと | Comic Book |
| Art | 増山修 | Art Direction |
| Sound | 早野利宏 | Sound Recordist |
| Production | 竹中信広 | Producer |
| Directing | 小島正幸 | Series Director |
| Sound | Kevin Penkin | Original Music Composer |
| Production | 礒谷徳知 | Producer |
| Production | 木村淳 | Producer |
| Sound | 山田陽 | Sound Director |
| Editing | 石井知 | Online Editor |
| Production | 山下愼平 | Producer |
| Sound | Kevin Penkin | Conductor |