The animated feature ChaO arrives as a playful reimagining of mermaid lore: in a softly futuristic setting labeled “20XX”, humans and merpeople share a fragile coexistence. The central plot follows a modest shipyard employee who finds his life upended when a mermaid princess named Chao unexpectedly proposes marriage, an event that spirals into public spectacle, career opportunity and an awkward, tender attempt at intimacy. Distributed in the U.S. by GKIDS and created at the boundary-pushing studio Studio4°C, the film foregrounds emotional sincerity amid surreal visuals and an eccentric cast.
Behind the camera is first-time feature director Yasuhiro Aoki, a two-decade veteran of Studio4°C who deliberately moved away from the subdued realism he had animated on big projects to craft a more elastic, comic style. The movie blends slapstick expression, painterly backgrounds and kinetic motion to create a world that feels both familiar and strange; Aoki’s choices emphasize character emotional beats as much as spectacle, and the result is a love story that uses visual invention to reveal inner life.
Reframing a mermaid romance
At its heart ChaO is a relationship story about learning to care for someone who is literally other. The mermaid princess—daughter of King Neptunus—appears in two striking manifestations: a waddling, oversized fish-like form on land and a more conventionally beautiful humanoid form underwater. The protagonist’s acceptance of the proposal is initially pragmatic: the marriage’s publicity greases the wheels for his ambitious shipbuilding project. Gradually, however, the public spectacle gives way to private discovery as the protagonist learns to love beyond appearances. Aoki leans into comedy and pathos to show how intimacy develops in a society that has normalized cohabitation with the fantastical.
Design sensibility and visual worldbuilding
The film’s aesthetic mixes loose, exaggerated character work with dense, atmospheric backdrops. Aoki drew from an earlier short he made for the 2006 anthology Amazing Nuts, applying an impressionistic, rubbery approach to movement that contrasts with his prior realistic animation credits. Location scouting in Shanghai informed the metropolitan vistas, and those cityscapes are rendered as twinkling, slightly alien canvases that support the strange domestic comedy. Character designer Hirokazu Kojima translated Aoki’s rough concepts into a roster of memorable silhouettes—giant eggs, bobble-headed commuters and other whimsical citizens—so that the city itself reads as a character in the film.
Dual physicalities: Chao’s two forms
One of the movie’s most deliberate choices is to make Chao’s land and sea bodies opposites. The landfish is designed as a broad, mascot-like creature whose physical comedy underlines her uninhibited personality, while the underwater version is created to be an “idealized” figure, emphasizing grace and traditional beauty standards. This contrast serves a narrative purpose: it forces the protagonist to reckon with what he values, and it makes his emotional growth visible. The use of contrasting forms becomes a device that pushes the audience to consider appearance, expectation and authenticity.
Story structure and peripheral lives
Rather than a linear romance, ChaO uses a framing device in which a future journalist interviews the protagonist about events that already occurred, turning the main romance into a recounted memory. This structure—invoking the idea of memory and interpretation—allows the film to withhold and reveal details at strategic moments. Beyond the leads, the movie populates its world with side stories: a robot inventor and a kung-fu practicer develop a quiet romance, while the journalist flirting with his mermaid editor suggests the world’s larger social fabric. Aoki intentionally makes supporting figures feel lived-in, even when they’re offscreen, so the city seems like a place where everyone carries a private narrative.
Why the framing matters
The decision to tell much of the plot via flashback gives the film thematic texture: the protagonist recounts moments he did not fully understand at the time, and that retrospective voice allows the audience to experience both discovery and doubt. Aoki has cited cinematic influences and chosen a framing that elevates the film above a straightforward romantic comedy; the device creates distance while also inviting empathy, and it reinforces the idea that personal transformation is often gradual and only visible in hindsight.
Ultimately, ChaO is both a comedy of manners and an affectionate fable about difference, heightening the ordinary with inventive visuals and heartfelt character work. The production champions motion and expression—the director’s deliberate break from realism—and positions background characters as active inhabitants of its world. Playing in theaters after its U.S. release in April, the film rewards repeat viewings: viewers who return will likely discover fresh details tucked into each densely composed frame.