Stephan
main character
MOVIE
6.8
My TrackerPLANNING
Episode: 0 / 1
My Score:
Anime DetailsFINISHED
Estimated watch time
1h 30m
⚡ 1 days at 5 eps/day
Tags & Tropes
Mermaid88%Female Protagonist79%Heterosexual79%Marriage79%Classic Literature79%Primarily Adult Cast79%Urban Fantasy79%Fairy Tale79%Male Protagonist60%Ships60%
overview details
Synopsis & Story
In a futuristic world where humans and mermaids coexist, ChaO follows Stephan, a mild-mannered office worker at a shipbuilding company, whose life is upended when he is suddenly proposed to by Chao — a princess from the mermaid kingdom. With no time to make sense of what’s happening, Stephan soon finds himself living with the unpredictable, wholehearted Chao. As her sincere love begins to break down his emotional barriers, an unexpected and touching romance begins to unfold. (Source: GKIDS)
Trailer
Watch on YouTubeWhere to Watch Officially
Availability, audio and subtitles vary by region and service.
Featured Cast & Voice Actors
Fans Who Watched This Also Loved
Aniphoria guide
ChaO: should you watch it?
At a glance
ChaO has been met with mixed reactions, with an average AniList score of 68/100 — 50% of 471 ratings are 8/10 or higher.
It ranks #31 highest-rated film of 2025, and #26 most popular film of 2025 on AniList.
Of the 830 AniList users who started it, 4.3% dropped it, so it is rarely abandoned; 628 have finished it.
As a 90-minute film, it fits in a single evening.
Best for viewers who enjoy Fantasy, Romance — especially mermaid, female protagonist, heterosexual, marriage.
Main cast & creators
- Character design
- Hirokazu Kojima
- Music
- Takatsugu Muramatsu
Opening & ending themes
Endings
- ED1“ChaO!” by Kumi Kouda
Theme data from AnimeThemes.moe.
ChaO FAQ
- How long is ChaO?
- ChaO runs 90 minutes (1 h 30 min).
- Is ChaO finished?
- Yes. ChaO has finished airing — the final episode aired August 15, 2025.
- Is ChaO based on a manga?
- No. ChaO is an original anime story, not adapted from a manga or novel.
- Who animated ChaO?
- ChaO was animated by Studio 4°C.
- Where can I watch ChaO?
- ChaO is listed on Netflix, Hulu. Availability varies by region — check the streaming links on this page.