Ruka is a young girl whose parents are separated and whose father works in an aquarium. When two boys, Umi and Sora, who were raised in the sea by dugongs, are brought to the aquarium, Ruka feels drawn to them and begins to realize that she has the same sort of supernatural connection to the ocean that they do. Umi and Sora's special power seems to be connected to strange events that have been occurring more and more frequently, such as the appearance of sea creatures far from their home territory and the disappearance of aquarium animals around the world. However, the exact nature of the boys' power and of the abnormal events is unknown, and Ruka gets drawn into investigating the mystery that surrounds her new friends.
Unfortunately the movie Children of the Sea is not yet available on HBO Max.
| Visual Effects | Ken Yamamoto | Key Animation |
| Visual Effects | Hirokazu Kojima | Key Animation |
| Visual Effects | Tatsuzo Nishita | Key Animation |
| Visual Effects | Kazuhiko Yabumoto | Key Animation |
| Directing | Kenichi Konishi | Second Unit Director |
| Visual Effects | Kenichi Konishi | Supervising Animation Director |
| Visual Effects | Miyuki Ito | Color Designer |
| Visual Effects | Yuuya Geshi | Key Animation |
| Visual Effects | Nahoko Machida | Key Animation |
| Sound | Koji Kasamatsu | Sound Director |
| Visual Effects | Yumi Chiba | Key Animation |
| Visual Effects | Manabu Akita | Key Animation |
| Visual Effects | Yuta Yokoo | Key Animation |
| Visual Effects | Eri Irei | Key Animation |
| Visual Effects | Etsuko Yamamoto | Key Animation |
| Visual Effects | Daiki Harashina | Key Animation |
| Visual Effects | Takahiro Tanaka | Key Animation |
| Visual Effects | Yuichiro Komuro | Key Animation |
| Visual Effects | Toko Yatabe | Key Animation |
| Writing | Saku Konohana | Screenplay |
| Visual Effects | Tetsuro Kaku | Key Animation |
| Visual Effects | Yuuko Sera | Key Animation |
| Visual Effects | Rika Ota | Key Animation |
| Sound | Kenshi Yonezu | Theme Song Performance |
| Visual Effects | Yuuya Geshi | Animation Director |
| Visual Effects | Izumi Murakami | Animation Director |
| Visual Effects | Tomohiro Shinoda | Key Animation |
| Visual Effects | Yukiko Nagao | Key Animation |
| Visual Effects | Yasue Sosogi | Key Animation |
| Visual Effects | Manami Sugimoto | Key Animation |
| Visual Effects | Eri Taguchi | Key Animation |
| Writing | Daisuke Igarashi | Comic Book |
| Visual Effects | Akiko Itagaki | Key Animation |
| Visual Effects | Masahiko Kubo | Key Animation |
| Visual Effects | Takana Shirai | Key Animation |
| Visual Effects | Udo Komuro | Key Animation |
| Visual Effects | Ryo Imamura | Key Animation |
| Visual Effects | Takashi Mukouda | Key Animation |
| Visual Effects | Mari Futamatsu | Key Animation |
| Visual Effects | Takuya Saito | Key Animation |
| Visual Effects | Ran Kamezawa | Key Animation |
| Visual Effects | Tomoyo Kamoi | Key Animation |
| Visual Effects | Sanae Shimada | Key Animation |
| Visual Effects | Izumi Murakami | Key Animation |
| Visual Effects | Yosuke Kudo | Key Animation |
| Visual Effects | Maiko Kobayashi | Key Animation |
| Visual Effects | Nanako Tatsu | Key Animation |
| Visual Effects | Soichiro Kubo | Key Animation |
| Visual Effects | Saori Koike | Key Animation |
| Visual Effects | Kenichi Yamaguchi | Key Animation |
| Visual Effects | Shingo Ishikawa | Key Animation |
| Visual Effects | Yasuyuki Shimizu | Key Animation |
| Visual Effects | Saki Hasegawa | Key Animation |
| Visual Effects | Miki Kurihara | Key Animation |
| Visual Effects | Emi Matsunaga | Key Animation |
| Visual Effects | Hideyuki Sugiura | Key Animation |
| Visual Effects | Kayoko Ishikawa | Key Animation |
| Visual Effects | Yuki Oomori | Key Animation |
| Visual Effects | Hiroyuki Aoyama | Key Animation |
| Visual Effects | Kenji Hachizaki | Key Animation |
| Visual Effects | Shigeru Kimishima | Key Animation |
| Visual Effects | Ryota Furukawa | Key Animation |
| Visual Effects | China | Key Animation |
| Visual Effects | Shintaro Doge | Key Animation |
| Visual Effects | Shougo Furuya | Key Animation |
| Visual Effects | Kaori Hayashi | Key Animation |
| Visual Effects | Minami Seki | Key Animation |
| Visual Effects | Tatsumori Imoto | Key Animation |
| Visual Effects | Hitomi Kariya | Key Animation |
| Visual Effects | Ayako Hata | Animation Director |
| Visual Effects | Ayako Hata | Key Animation |
| Visual Effects | Yoshiko Hoshi | Key Animation |
| Visual Effects | Ryo Konishi | Key Animation |
| Art | Sadayuki Arai | Background Designer |
| Sound | Mika Yamaguchi | Foley Artist |
| Production | Junya Okamoto | Associate Producer |
| Production | Keiji Kameyama | Executive Producer |
| Art | Aiwa Narihata | Background Designer |
| Sound | Koji Kasamatsu | Sound Effects |
| Production | Hajime Inoue | Executive Producer |
| Art | Mika Nishimura | Background Designer |
| Production | Nobumasa Sawabe | Co-Producer |
| Art | Ryoko Ina | Background Designer |
| Production | Masakazu Kubo | Executive Producer |
| Production | Eiko Tanaka | Executive Producer |
| Production | Akito Takahashi | Associate Producer |
| Art | Sara Hasegawa | Background Designer |
| Visual Effects | Kenichiro Akimoto | CGI Director |
| Production | Eiko Tanaka | Producer |
| Production | Keiji Ota | Executive Producer |
| Crew | Miyuki Ito | Special Effects |
| Production | Ayumi Inoguchi | Co-Producer |
| Production | Lovinia Chiu | Executive Producer |
| Production | Kimihisa Tsutsui | Executive Producer |
| Editing | Kiyoshi Hirose | Editor |
| Art | Kosuke Hayashi | Background Designer |
| Visual Effects | Takafumi Ishida | CG Animator |
| Visual Effects | Takanori Nakajima | CG Animator |
| Directing | Ayumu Watanabe | Director |
| Art | Shinji Kimura | Art Direction |
| Visual Effects | Kenichi Konishi | Character Designer |
| Sound | Joe Hisaishi | Original Music Composer |
| Visual Effects | Moaang | Key Animation |
| Visual Effects | MYOUN | Key Animation |
