It was revealed on November 24th that the manga "Chiikawa" by Nagano, a popular illustrator of "X", will be adapted into a film, titled "The Secret of Chiikawa the Mermaid Island" and released in the summer of 2026. The TV anime adaptation of the work has been airing since 2022, but this will be the first time it has been adapted into a film. The popular feature-length story "Siren Arc", which Nagano wrote specifically for the film, will be adapted into an anime. Nagano will be writing the script for the anime, and Oikawa Kei, who has worked on the "Uma Musume Pretty Derby" series, will be directing. The anime will be produced by Cygames Pictures, which also produced the film "Uma Musume Pretty Derby: The Door to a New Era".
Nagano commented, "Chiikawa has been decided to be made into a movie!! The title is 'The Secret of Mermaid Island.' It is a story about going to an island that was posted on X from March to November 2023. This will be Chiikawa' journey on the big screen for the first time. I hope you will look forward to it!"
A teaser visual has been released showing Chiikawa, Hachiware, and Usagi on a boat. Chiikawa and the Chiikawa are wearing flower crowns and loincloths, gazing up at the beautiful full moon and night sky.
In "Siren Arc," one day, Chiikawa arrive on a suspicious flyer that reads, "Invitation to a Special Island." The flyer states, "Earn 100 times the reward for simple subjugation on the island," and "Limited island ramen and limited sweets, all sweet and spicy food essentially free." Though suspicious, the group is lured to the island by the reward and ends up spending an unforgettable summer there.
"Chiikawa" is a manga that Nagano has been posting on X since 2020. The contrast between the cute little characters and the harsh worldview has made it popular, with X now having over 4.39 million followers. It has won the Japan Character Award Grand Prix three times, and the short anime that began airing in 2022 has been viewed over 400 million times on YouTube, making it a hugely popular content loved not only in Japan but all over the world.
