The highly anticipated theatrical film Eiga Chiikawa: Ningyo no Shima no Himitsu (Chiikawa the Movie: The Secret of Mermaid Island) has unveiled its full cast, opening theme song details, and a new trailer, building excitement for its July 24 release across Japan. Distributed by TOHO, the film adapts the wildly popular Chiikawa franchise created by Nagano, which began as a webcomic and has since exploded into a cultural phenomenon spanning merchandise, a hit TV anime, and now its first feature film.
Key Announcement Details
The film is produced by Cygames Pictures, the studio behind the original TV anime and Apocalypse Hotel, with Kei Oikawa (Hinamatsuri, Uma Musume Pretty Derby Season 3) in the director's chair. Nagano himself is handling the script, adapting the popular "Siren Arc" / "Island Arc" that was originally serialized on X (formerly Twitter) from March to November 2023.
- Director: Kei Oikawa (Cygames Pictures)
- Script: Nagano (original creator)
- Character Design: Tomoko Tsuji
- Music: Shūgo Tokumaru, Chikara Uemizutaru
- Opening Theme: "Kutsuzure" (Shoe Sore) performed by Makoto Tanaka (voice of Hachiware), lyrics by Nagano
- Insert Song: "Shima no Uta" (Island Song)
Cast
- Makoto Tanaka as Hachiware (also performing the opening theme)
- Tsuguo Mogami as Shimajiro
- Minori Suzuki as Siren
Story Synopsis
The film follows Chiikawa and Hachiware as they encounter a mysterious rabbit carrying a flyer advertising an invitation to a "special island" with promises of rewards, easy hunts, and limited-edition island ramen and sweets. Suspicious of the offer, Rakko joins them on what becomes a far more mysterious adventure than anticipated — uncovering the secrets of Mermaid Island.
Community Reception
The trailer, which amassed over 337,000 views within 14 hours of its release on YouTube, has generated significant buzz among fans. The Chiikawa franchise, already a massive cultural force in Japan with ubiquitous merchandise, character collaborations, and a devoted fanbase, has seen excitement build steadily since the film's initial announcement. Fans on social media have praised the film's vibrant animation style and the faithful adaptation of the beloved manga arc, with particular enthusiasm for Nagano's direct involvement in the screenplay.
Visual/Video
What This Means
Chiikawa has become one of the most recognizable franchises in modern Japanese pop culture, rivaling Sanrio's Hello Kitty in merchandise presence and social media engagement. A feature film represents a significant milestone for the franchise, potentially expanding its already massive domestic audience. With TOHO's distribution power and Cygames Pictures' proven track record with the TV series, the film is positioned as one of the biggest animated releases of the Summer 2026 season in Japan. International release details have not yet been announced.