Name: ChaO
Director: Yasuhiro Aoki
Genre: Animation, Fantasy, Romance
Released: 2025-08-15T00:00:00+00:00
Duration: 90 min
Cast: Ouji Suzuka, Anna Yamada, Kavka Shishido, Yuuichirou Umehara, Kenta Miyake

In ChaO, a mermaid princess proposes to a clerk at a shipbuilding company, the city sells their union as the wedding of the century, and the bride, by the account of the critics who have seen it, spends much of the film as a fish the size of a person, walking the streets of a future Shanghai. This is the first feature directed by Yasuhiro Aoki, and its premise works like a deliberate act of sabotage against the mermaid story as cinema has learned to tell it, from Andersen’s silent sacrifice to the Disney princess.

The film is now in Korean cinemas after a long international run that began with the Jury Prize in the feature competition at Annecy. The laurel matters less than the position Aoki takes. He has said that animation now “just seems to be going in one single direction,” and ChaO is built as a refusal of that drift, from its childlike character designs to the densely drawn city they move through.

The casting points the same way. Stephan is voiced by Ouji Suzuka and ChaO by Anna Yamada, two actors for whom, by their own account, voice work is the exception: Suzuka told Real Sound he had not expected to work on an animated film again, and Yamada admitted the job made her nervous. Around them sit Kavka Shishido, Yuuichirou Umehara, Kenta Miyake, Anna Tsuchiya and Ryota Yamasato. The trailer, released by GKIDS for the North American run, sells the comedy of incompatibility rather than the romance; Real Sound’s description of the Japanese trailer lists an electric eel for breakfast, ice cream swallowed whole and fireworks set off inside the flat. A film cast this way wants to be read as a broad comedy first and an anime second, and Aoki said as much when he told Anime News Network that Disney is “really good at making entertaining films” and that he wanted ChaO to be that kind of movie.

He also said the opposite half of the sentence: “if we just followed in Disney’s footsteps, we couldn’t go beyond that.” Aoki comes to his first feature late and from inside the house. Cartoon Brew describes him as a Studio 4°C mainstay who animated on Masaaki Yuasa’s Mind Game and on Princess Arete, and the seed of ChaO is older than the project itself. Aoki traces it to the animated piece he made for Koda Kumi’s song “Twinkle,” his segment of the omnibus Amazing Nuts!, after which singer and director talked about one day making a feature together. Koda now sings the theme, “ChaO!”, and told Real Sound that seeing it happen after nineteen years felt like a fated encounter.

The institutional lineage is just as telling. Studio 4°C is run by Eiko Tanaka, who served as line producer on My Neighbor Totoro and Kiki’s Delivery Service before building a studio whose features rarely resemble one another: Mind Game, Tekkonkinkreet, Children of the Sea. According to the film’s Korean distributor, Tanaka began preparing ChaO in 2016 and chose Andersen’s The Little Mermaid as the starting point precisely because a story everyone knows would make the studio’s reading of it more visible. The same materials say production was at one point in danger of stopping. It took seven years and, according to the Fantasia festival’s programme notes, more than 100,000 drawings, made by hand one at a time.

What the film argues with that labour is a matter of form, and Aoki is explicit about it. He invokes heta-uma, the Japanese style of deliberately “not very good” drawing that can look “almost like a kid’s drawing,” and sets those figures, designed by Hirokazu Kojima, against backgrounds he describes as very detailed: a Shanghai chosen, he told Cartoon Brew, because new and old coexist there. The contrast is the point, he says, because the team “wanted to try something that only animation can do.” The structure rhymes as well. Aoki describes three confessions running in parallel: Stephan’s, a journalist’s to his editor-in-chief, who turns out to be a mermaid too, and that of Stephan’s friend Roberta. The premise suggests a comedy of remarriage run backwards, in which the wedding comes first and the courtship has to be earned afterwards.

That inversion is also where the film’s weakest point may lie. Stephan is swept into the marriage without understanding it, and the plot, as every synopsis frames it, is the slow thaw of a reluctant man before a woman whose devotion never wavers. When Anime News Network put it to Aoki that some viewers might find Stephan cruel to ChaO, he did not take the bait: “I’m on Stefan’s side,” he said, adding, “I was drawing myself.” Nothing in the published material shows whether the film questions Andersen’s old asymmetry, where the mermaid gives everything and the man merely accepts, or simply repeats it with a fish costume and a better joke. The broad audience Aoki wanted has not clearly arrived either. Anime News Network reported US$70,254 for the first three days of the American run and US$112,217 after a week, the numbers of a festival favourite rather than a crossover.

The critical record is warm but measured. Rotten Tomatoes lists 86 percent positive reviews from 28 critics; Metacritic’s weighted score is 67 from five. Simon Abrams gave it three and a half stars out of four at RogerEbert.com and called it “a real pleasure to watch and listen to.” The Korean distributor notes that the Annecy Jury Prize made ChaO the first Japanese animated feature in eight years to take that award. Behind the camera, the screenplay is credited to Saku Konohana, the score to Takatsugu Muramatsu, the art direction to Hiroshi Takiguchi, with Kojima as chief animation director and Studio 4°C producing.

A teal-haired young woman in a city street in a still from the Studio 4°C animated film ChaO (2025) — A scene from *ChaO* (2025), directed by Yasuhiro Aoki

ChaO opened in Japan through Toei on August 15, 2025. GKIDS released it in North American theaters on April 10, 2026, followed by a digital release on June 23 and a Blu-ray on September 22. France had it from May 13 through Eurozoom, and the Korean release followed on October 21, 2026, through Media Castle at Megabox, rated for all ages and running 89 minutes and 40 seconds.

Andersen’s mermaid gave up her voice to walk on land. Aoki’s keeps her voice, walks on land as a fish, and leaves the man to do the changing. Whether the film believes in that bargain or only finds it funny is the thing Korean audiences can now judge for themselves.