A mermaid princess picks a timid office clerk as her husband-to-be, and the whole city has to adjust. ChaO is a 2025 Japanese animated feature directed by Yasuhiro Aoki that treats a classic fish-out-of-water setup as a romantic comedy about learning to let someone in.
What is ChaO about?
Stephan keeps his head down. He works a desk job in a near-future metropolis built so that humans and mermaids share the same streets and the same paperwork, and he has arranged his life around not being noticed. That arrangement collapses the day Chao, a princess of the mermaid kingdom, announces that she intends to marry him. The proposal lands before any courtship, and the film follows what happens when a man who has never been chosen is chosen loudly and in public. Chao moves in. She is impulsive, direct and incapable of hiding what she feels, and her presence turns Stephan's quiet apartment into a place where things actually happen. The comedy comes from the collision between her royal confidence and his habit of apologising for taking up space; the romance comes from watching that habit loosen. Around the pair, the mixed society of the setting supplies both spectacle and friction, because a match between mermaid royalty and an ordinary human is a public matter as much as a private one.
About the cast
The Japanese voice cast is headed by Ouji Suzuka and Anna Yamada, with Kavka Shishido, Yuuichirou Umehara, Kenta Miyake, Shunsei Ōta, Anna Tsuchiya and Kunihiro Kawashima filling out the ensemble. Yasuhiro Aoki directs, and the performances lean into the contrast the story depends on: one voice all restraint, the other all appetite.
Context & significance
Romance anime about an unlikely couple is a crowded field, but ChaO stands out by placing its love story inside a worked-out fantasy society rather than a school corridor. The humans-and-mermaids premise lets the film play with design, from an underwater monarchy to a city engineered for two kinds of citizens, while keeping its emotional stakes small and recognisable. At ninety minutes it moves briskly, which suits a story whose engine is one character's refusal to wait. Viewers who enjoy gentle comedies about mismatched partners will find the premise an easy one to settle into.
Watching ChaO on Ktime
ChaO streams on K-Time with both a Persian dub and Persian subtitles, so you can hear the story in Farsi or follow the original Japanese performances with Farsi text. Watching requires a K-Time account login; the catalogue page itself is free to browse. K-Time serves the Persian-speaking diaspora with a Farsi interface on phone, tablet and television.