Children of the Sea

Ruka lives near the coast in a world where family is not simple and the sea feels like a second home. Her father works at an aquarium, and her life is shaped by tides and routine. When two boys, Umi and Sora, reared by dugongs, arrive at the aquarium, she senses a strange kinship that seems to awaken something inside her. The pair carry a power linked to unusual occurrences across the oceans, from strange creatures appearing far from their home waters to aquarium animals vanishing worldwide. The exact source of their gift and the meaning of the events remain mysterious, drawing Ruka toward the unknown and her own hidden connection to the sea and its mysteries.

Directed by Ayumu Watanabe, this 2019 feature adapts the manga by Daisuke Igarashi and Saku Konohana. The production by Studio Colorido blends watercolor and CGI to create immersive underwater sequences and sprawling coastal vistas. That balance helps to ground the fantastical elements in a tangible world.

Critics note the film's luminous ocean visuals and its quiet treatment of family and belonging, framed by a bond between humans and the sea. The story looks at communities adapting to odd events and asks viewers to consider responsibility toward nature and the creatures we share the world with.

Box office data for this title is not widely reported, reflecting a limited international release and a focus on festival and art-house screenings rather than wide commercial distribution. As a result, earnings are modest and the film found audiences primarily through film festivals and streaming.

Its visual language and themes of kinship with the sea resonated with audiences who favor imaginative storytelling over action. While not a blockbuster, the film contributed to conversations about humanity's relationship with the ocean and encouraged young viewers to think about environmental issues.