With Children of the Sea, director Ayumu Watanabe adapted a manga by Daisuke Igarashi, striving to retain the qualities in the source material that he'd originally responded to, while making the changes necessary to bring its characters into a new medium.
The director's Oscar-contending animated feature centers on Ruka, a young girl who finds herself drawn into a mystery of the sea. Encountering two boys that were raised in the ocean, at the aquarium where her father works, the girl seeks answers about their supernatural powers, and how they're connected to strange events involving sea creatures around the world.
When Watanabe first read the manga on which his GKIDS film is based, he responded immediately to its visual style. “I was reading [Igarashi's] manga before Children of the Sea came out, so I was already a fan, and I knew his artwork well,” the director tells Deadline. “For me, the variation between simple lines and sometimes very detailed [illustrations] was something I was really drawn to.”
Fundamentally, the director notes, the designs for his film's characters came straight out of the manga. “[But] what's really interesting is that if you just lift up a manga-designed character and stick it in animation, it's all out of balance, and it ends up not being what you thought it would be,” he says. “We actually got the blessing of the manga artist, because he understood that it's not a one-to-one transfer. The manga artist let the character designer do what he needed to do, in order for it to translate well into animation.”
For Watanabe and CGI supervisor Kenichiro Akimoto, one of the greatest challenges of bringing Children of the Sea to life had to do with realistically animating all of the kinds of marine life seen in the film. “For fish life and the environment, we took trips to the ocean, and did a lot of research at aquariums. We were also able to work with a university, whose speciy is to look at the movement of fish. So, we were able to look at them very closely,” Akimoto says. “What was really difficult is that in live-action, when you're on the street, you have perspective, because you have cars, you have electric poles, so you understand depth. But [in this case], you just had a blank slate of ocean. It was especially difficult to create depth, when you're working with a clean slate.”
Like another 2019 GKIDs title, Makoto Shinkai's Weathering with You, Watanabe's film is concerned with climate change. “But it's not just holding a sign that says, 'Keep the oceans clean.' It's more about portraying something beautifully, and then having the audience think, 'How can I maintain that? What's the answer?' And realize that, 'I'm part of this world, too,'” the director explains. “Once you understand that, you are not just an individual. You are one of many people on this Earth, and we're all connected.”