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 | Eri Taguchi | Key Animation |
| Visual Effects | Kenichi Konishi | Supervising Animation Director |
| Directing | Kenichi Konishi | Second Unit Director |
| Writing | Saku Konohana | Screenplay |
| Writing | Daisuke Igarashi | Comic Book |
| Visual Effects | Miyuki Ito | Color Designer |
| Sound | Koji Kasamatsu | Sound Director |
| Sound | Kenshi Yonezu | Theme Song Performance |
| Visual Effects | Ayako Hata | Animation Director |
| Visual Effects | Yuuya Geshi | Animation Director |
| Visual Effects | Izumi Murakami | Animation Director |
| Visual Effects | Yuuya Geshi | Key Animation |
| Visual Effects | Tatsuzo Nishita | Key Animation |
| Visual Effects | Kaori Hayashi | Key Animation |
| Visual Effects | Sanae Shimada | Key Animation |
| Visual Effects | Akiko Itagaki | Key Animation |
| Visual Effects | Nahoko Machida | Key Animation |
| Visual Effects | Kazuhiko Yabumoto | Key Animation |
| Visual Effects | Minami Seki | Key Animation |
| Visual Effects | Izumi Murakami | Key Animation |
| Visual Effects | Tomohiro Shinoda | Key Animation |
| Visual Effects | Hirokazu Kojima | Key Animation |
| Visual Effects | Ayako Hata | Key Animation |
| Visual Effects | Takashi Mukouda | Key Animation |
| Visual Effects | Masahiko Kubo | Key Animation |
| Visual Effects | Kenji Hachizaki | Key Animation |
| Visual Effects | Tomoyo Kamoi | Key Animation |
| Visual Effects | Yukiko Nagao | Key Animation |
| Visual Effects | Maiko Kobayashi | Key Animation |
| Visual Effects | Takahiro Tanaka | Key Animation |
| Visual Effects | Tetsuro Kaku | Key Animation |
| Visual Effects | Shigeru Kimishima | Key Animation |
| Visual Effects | Ryota Furukawa | Key Animation |
| Visual Effects | Yuuko Sera | Key Animation |
| Visual Effects | Yasuyuki Shimizu | Key Animation |
| Visual Effects | Kayoko Ishikawa | Key Animation |
| Visual Effects | Yumi Chiba | Key Animation |
| Visual Effects | Tatsumori Imoto | Key Animation |
| Visual Effects | Saki Hasegawa | Key Animation |
| Visual Effects | Yuki Oomori | Key Animation |
| Visual Effects | Manabu Akita | Key Animation |
| Visual Effects | Takana Shirai | Key Animation |
| Visual Effects | Yasue Sosogi | Key Animation |
| Visual Effects | Mari Futamatsu | Key Animation |
| Visual Effects | Nanako Tatsu | Key Animation |
| Visual Effects | Miki Kurihara | Key Animation |
| Visual Effects | Soichiro Kubo | Key Animation |
| Visual Effects | Manami Sugimoto | Key Animation |
| Visual Effects | Emi Matsunaga | Key Animation |
| Visual Effects | Saori Koike | Key Animation |
| Visual Effects | Udo Komuro | Key Animation |
| Visual Effects | Etsuko Yamamoto | Key Animation |
| Visual Effects | Yuichiro Komuro | Key Animation |
| Visual Effects | Yuta Yokoo | Key Animation |
| Visual Effects | Hideyuki Sugiura | Key Animation |
| Visual Effects | Kenichi Yamaguchi | Key Animation |
| Visual Effects | Shingo Ishikawa | Key Animation |
| Visual Effects | Yoshiko Hoshi | Key Animation |
| Visual Effects | Takuya Saito | Key Animation |
| Visual Effects | Rika Ota | Key Animation |
| Visual Effects | Hitomi Kariya | Key Animation |
| Visual Effects | China | Key Animation |
| Visual Effects | Ryo Imamura | Key Animation |
| Visual Effects | Eri Irei | Key Animation |
| Visual Effects | Yosuke Kudo | Key Animation |
| Visual Effects | Ran Kamezawa | Key Animation |
| Visual Effects | Toko Yatabe | Key Animation |
| Visual Effects | Daiki Harashina | Key Animation |
| Visual Effects | Shintaro Doge | Key Animation |
| Visual Effects | Shougo Furuya | Key Animation |
| Visual Effects | Hiroyuki Aoyama | Key Animation |
| Visual Effects | Ryo Konishi | Key Animation |
| Art | Ryoko Ina | Background Designer |
| Art | Sadayuki Arai | Background Designer |
| Art | Sara Hasegawa | Background Designer |
| Art | Mika Nishimura | Background Designer |
| Art | Aiwa Narihata | Background Designer |
| Sound | Mika Yamaguchi | Foley Artist |
| Sound | Koji Kasamatsu | Sound Effects |
| Production | Nobumasa Sawabe | Co-Producer |
| Production | Ayumi Inoguchi | Co-Producer |
| Visual Effects | Kenichiro Akimoto | CGI Director |
| Production | Akito Takahashi | Associate Producer |
| Production | Junya Okamoto | Associate Producer |
| Production | Eiko Tanaka | Executive Producer |
| Production | Eiko Tanaka | Producer |
| Production | Keiji Kameyama | Executive Producer |
| Production | Masakazu Kubo | Executive Producer |
| Production | Keiji Ota | Executive Producer |
| Production | Kimihisa Tsutsui | Executive Producer |
| Production | Hajime Inoue | Executive Producer |
| Production | Lovinia Chiu | Executive Producer |
| Crew | Miyuki Ito | Special Effects |
| 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 |
| Visual Effects | Kenichi Konishi | Character Designer |
| Art | Shinji Kimura | Art Direction |
| Sound | Joe Hisaishi | Original Music Composer |
| Visual Effects | Moaang | Key Animation |
| Visual Effects | MYOUN | Key Animation |
