timelesz's new song "Kienai Hanabi" has been chosen as the theme song for the animated film 'Kimi to Hanabi to Yakusoku to,' starring member Shori Sato.

Based on the novel by Kaori Mado, the film is set around the Nagaoka Fireworks Festival in Niigata and follows the romance between a socially awkward high school student named Makoto Natsume and heroine Aki Hayama. Sato voices Makoto, while Nanoka Hara voices Aki.

"Kienai Hanabi" is a love song that was written specifically for the film. It carries the theme that while fireworks eventually fade, the memories shared together remain in the heart. Sato said, "Fireworks may shine for only a moment, but the feelings they leave behind can stay deep in your heart forever. I hope we were able to create a theme song like that."