Timelesz Theme Song and New Cast Revealed for Shori Sato Anime Film
The casting of Rie Takahashi and Natsuko Yokozawa, combined with the theme song performed by the lead actor's own group, gives the film a built-in audience draw from both anime voice acting fans and idol followers.
Reporting from 4 sources: Eiga Natalie, Comic Natalie, Anime Hack (anime.eiga.com), Anime Anime.
The upcoming anime film "You, Fireworks, and a Promise" has revealed its theme song and two new cast members. The idol group timelesz will perform the song "Kienai Hanabi" for the film, which stars group member Shori Sato in his first lead anime film role. Voice actress Rie Takahashi joins the cast as Haru, a mysterious girl who appears before the protagonist, and comedian Natsuko Yokozawa, a Niigata native, voices Makoto's mother Yukari. The film is based on the novel by Madoroka and is set against the Nagaoka Festival Grand Fireworks Display in Niigata, one of Japan's three major fireworks festivals. The story follows high school student Makoto Natsume, voiced by Sato, who is approached by classmate Aki Hayama, voiced by Nanoka Hara. Aki tells Makoto that her great-grandmother said she would one day meet him, and the two are drawn into a mystery involving a picture of a firework and a promise made across 81 years. The main trailer featuring the theme song has been released. The film opens nationwide on July 17, 2026. Director Kei Suzuki, known for "Tower of God: Workshop Battle," helms the project, with animation production by SynergySP and Answer Studio.
The screenplay is by Kohei Mori, and the character design is by Yuji Watanabe, based on original designs by Akamoku. Michihiko Umezawa handles planning and production. Shin-Ei Animation is the planning and production company, with distribution by Shochiku and Shin-Ei Animation. Publicity cooperation comes from Showgate. The project is supported by Niigata Prefecture, Nagaoka City, the Niigata Prefecture Tourism Association, and the Nagaoka Fireworks Foundation.
Rie Takahashi, who voices the mysterious girl Haru, said it was her first time trying the Nagaoka dialect. She learned from guide audio in the recording footage and was checked on the day by people from Nagaoka. "During recording, there were phrases that some people in Nagaoka use and others don't, and for newly added lines, they demonstrated them," she said. "It was a dense experience, recording while staying close to Nagaoka!"
Natsuko Yokozawa, a Niigata native, voices Makoto's mother Yukari. She said she was told to imagine "a working mom who works hard as a hair and makeup artist." "I was nervous about whether I could produce a voice that watches over her son while working," she said. "I was moved by my son's straightforwardness, and I hope I can give him a good push."
The main trailer and main visual have also been released. The song information was released early on May 14. Shori Sato said of the theme song, "Fireworks may be a momentary brilliance. But they also leave eternal memories deep in the heart. I think we were able to create such a theme song."
Synthesized by Yomimono from the 4 cited sources below, including Japanese-language reporting where cited, then editorially reviewed before publishing.
Sources
- Eiga Natalie 佐藤勝利主演の映画「君と花火と約束と」主題歌はtimelesz、新キャストに高橋李依・横澤夏子（本予告・コメントあり）
- Comic Natalie 「君と花火と約束と」本予告公開、主題歌はtimelesz 高橋李依と横澤夏子が出演（動画あり / コメントあり） - コミックナタリー
- Anime Hack (anime.eiga.com) アニメ映画「君と花火と約束と」主題歌はtimeleszの新曲、本予告も披露 高橋李依、横澤夏子の出演も決定
- Anime Anime timelesz 佐藤勝利 主演アニメ映画「君と花火と約束と」主題歌はグループ書き下ろし曲「消えない花火」に決定【コメントあり】 | アニメ！アニメ！