A teaser trailer for Eiga Chiikawa: Ningyo no Shima no Himitsu (Chiikawa the Movie: Secret of the Mermaid Island) has left the docks, revealing a sneak peek of the popular mascot’s first theatrical anime outing. It was also revealed that the movie will begin screening on July 24.
Chiikawa is the creation of Nagano, coming into being as the character of a webcomic on X (formerly Twitter). The upcoming movie is based on the Siren Arc storyline that was originally posted on X from March 2023 to November 2023.
Chiikawa has inspired social media and LINE stamps, goods, and a Doga Kobo-produced short anime, which began in 2022 and has almost 300 episodes as of November 2025. The character won the Grand Prix at the Japanese Character Award in 2022, 2024, and 2025.
Staff
• Director: Kei Oikawa (Umamusume: Pretty Derby Season 1 and 2)
• Scriptwriter: Nagano
• Character designer: Tomoko Tsuji (Umamusume: Pretty Derby)
• Animation production: CygamesPictures
Cast
• Haruka Aoki as Chiikawa
• Masato Tanaka as Hachiware
• Ari Ozawa as Usagi
