Nagano's viral phenomenon has reached an unprecedented theatrical milestone. The franchise's debut feature film, Chiikawa The Movie: Secret of the Mermaid Island, has officially earned over 11 billion yen (approximately $75 million USD) with 7.66 million tickets sold within its first 31 days in Japanese theaters.
Interactive Theatrical Expansion
To celebrate the film's monumental commercial success, the production committee has confirmed a lineup of special interactive event screenings nationwide. Starting September 5, theaters across Japan will roll out 4DX sensory screenings featuring dynamic seat motion, wind, and water splash effects tailored to the film's climactic battle sequences against the Siren and Usagi's energetic musical moments.
In addition to 4DX formats, special voice-allowed cheer screenings are set for September 11, allowing audiences to collectively chant Hachiware's famous rallying cry, "Nantokanaree!!" (It'll work out!!). A second interactive event on September 23 will introduce wirelessly synchronized lightsticks that automatically shift colors in real time alongside on-screen character entries and musical cues.
Adapting the Fan-Favorite Arc
The film adapts the acclaimed Siren Arc from Nagano's original web manga—a narrative pivot widely praised by readers for contrasting the characters' delicate design language with high-stakes peril and emotional narrative complexity. As theatrical attendance remains high, special farewell greeting events featuring mascot appearances will also continue throughout September.



