’ChaO’ review: Anarchic Japanese anime imagines a fantastical near-future Shanghai

Dir: Yasuhiro Aoki. Japan. 2025. 90mins

A lowly employee at a shipping company in a fantasy near-future Shanghai finds himself married to a mermaid princess in this comedy of romantic missteps and cultural misunderstandings. It is a premise that, in the wrong hands, could be rather twee, but veteran animator Yasuhiro Aoki’s terrific feature-directing debut leans into the grotesque and absurd elements of human-merperson relations. Visually spectacular and energetic in style, this is a bracingly anarchic piece of storytelling that announces a distinctive new voice in Japanese anime.

Announces a distinctive new voice in Japanese anime

Aoki has previously directed several short films and served as key animator or animation director on productions including Neon Genesis Evangelion, Digimon: The Movie and, most recently, The Lord Of The Rings: The War Of The Rohirrim. This picture, from Studio4°C, shares something of the production company’s maverick approach to features including Tekkonkinkreet (2006), which is a similarly twisted take on a fairytale premise. ChaO, which premieres in the main competition at Annecy, will subsequently screen at Fantasia and should be a title of considerable interest for specialist animation distributors. Toei releases it in Japan on August 15, while GKids has picked up North American rights.

The film opens in a richly realised fantasy Shanghai, where humans and merpeople have learned to live together in harmonious coexistence. It is an extraordinary piece of world-building, rendered in a vivid, impressionistic, sometimes almost abstract combination of animation techniques. Humans and merpeople have their own travel infrastructures – the city’s human inhabitants take the train, the sea-dwellers zip around using handy water tubes.

Running late for an assignment, human cub reporter Juno (voiced by Ota Shunsei) hops into a water tube, hoping to save time. He misses out on the story anyway, but stumbles onto a far bigger one: on a boat at the harbour, he spots Stephan (Oji Suzuka), the man whose relationship with the mermaid princess ChaO (Anna Yamada) heralded this golden era of peace between the peoples of the land and the sea. He stows away, intent on learning Stephan’s story from the man himself. It is a neat framing device, which takes on a satisfying further dimension by the close of the picture.

The main body of the story, as recounted to Juno, tells of Stephan’s initially reluctant romance with the mermaid who, for much of the early stages of their courtship and marriage, takes the form of an enormous orange fish. Stephan, demoted by his despotic boss President Sea (Ryota Yamasato) to mop the deck of the company’s flagship boat, is swept overboard. He regains consciousness in a hospital bed, as a giant fish gazes at him with love in her eyes and a proposal of marriage on the table. Spotting a business opportunity, President Sea fast-tracks the hapless Stephan into wedded bliss. There is a goofy, slapstick humour to much of the picture: in her fish form, ChaO is a well-meaning klutz with a talent for destruction (fortunately, she also has a sylph-like semi-humanoid form, as a beautiful blue-haired siren).

Thanks to voracious media attention, the pair become instant celebrities and the subject of intense scrutiny whenever they appear in public. They are an eye-catching couple certainly, but the film’s eclectic character design means that ChaO is by no means the weirdest creature wandering the streets of Shanghai. Some characters, Stephan included, have a conventional human form. Others, like President Sea, are huge, egg-shaped entities. And then there are still others who, for no apparent reason, have monstrous, oversized heads. It all contributes to the film’s gloriously lawless approach to storytelling and a gleefully untrammelled spirit. And while there are moments when ChaO’s enthusiastic embrace of chaos can come at the expense of clarity, for the most part it is an absolute blast.