ChaO

Set in a futuristic society where humans and mermaids live together, the story follows Stephan, a quiet office worker whose life changes abruptly when he receives a marriage proposal from Chao, a princess of the mermaid kingdom. As he is forced to navigate this unexpected situation and share his life with the spirited and unpredictable princess, Chao's sincere affection gradually breaks through his emotional defenses.

This Japanese animated fantasy romance was produced by STUDIO4℃ and directed by Yasuhiro Aoki. It is the second of three films directed by Aoki, following Batman: Gotham Knight and preceding LA PANTHÈRE DE CARTIER. The screenplay was written by Saku Konohana and produced by Eiko Tanaka. The voice cast features Ouji Suzuka as Stephan and Anna Yamada as Chao, with supporting roles performed by Kavka Shishido, Yuuichirou Umehara, Kenta Miyake, and Shunsei Ōta.

The film has a runtime of 90 minutes and was created by a credited crew of 71 people. Since its release on August 15, 2025, it has received a positive response from viewers, maintaining a rating of 8.2/10 on TMDB based on 15 votes.