Shori Sato of the eight-member group timelesz has been cast as the lead in the animated feature film “Kimi to Hanabi to Yakusoku to” (“You, Fireworks, and a Promise”), set to release on July 17, 2026. Based on the novel by Kaori Mado (published by Shogakukan’s Gagaga Bunko imprint on December 18, 2025, with illustrations by Akamoku), this movie tells a heartrending love story set against the backdrop of one of Japan’s major fireworks festivals.
Sato plays the protagonist, Makoto Natsume, marking his first starring role in an animation work and his long-awaited debut as a voice actor. Throughout his career, Sato has demonstrated remarkable versatility across a wide range of genres, including starring in the 2013 drama “49,” co-starring in the 2022 drama “Akai Nurse Call” with frequent STARTO acting collaborator Riko Fukumoto, and appearing in the recently released film “Kyojo: Reunion” starring Takuya Kimura. In this anime film, through subtle and nuanced voice acting, he delicately portrays a high school boy who struggles with interacting with others and lacks self-confidence.
Joining him is Nanoka Hara as Aki Hayama, whom Makoto falls in love with. Known for her continuous appearances in high-profile works such as “Suzume,” “Mieruko-chan,” and the live-action adaptation of “Oshi no Ko,” Hara carefully portrays Aki‘s complex emotions—a gifted class president admired by other students, who finds herself swept up by the whims of fate after discovering a certain painting.
This coming-of-age romance story is set during the Nagaoka Fireworks Festival in Niigata, which attracts hundreds of thousands of spectators each year who come to marvel at its beautiful displays. Makoto and Aki, both 15-year-old high school students living in Tokyo, are brought together by a painting depicting fireworks bursting in the sky. As they are drawn into the mystery of the painting and the fate that surrounds it, the duo is forced to make a crucial decision within a limited amount of time.
Kei Suzuki (assistant director in “City Hunter The Movie: Angel Dust”) is directing the film at Synergy SP and The Answer Studio, with a screenplay by Kohei Mori. Yuji Watanabe (“Flag” guest character designer and animation director for 6 episodes) designed the characters, while Michihiko Umezawa (“The Dangers in My Heart,” “A Couple of Cuckoos”) planned and produced the project with Shin-Ei Animation, which is handling distribution with Shochiku.
The newly unveiled teaser visual depicts Makoto and Aki framed by fireworks lighting up the night sky of Nagaoka. Makoto reaches out with all his might as if trying to convey something while gazing up at the dazzling display, while Aki, being pulled along by his hand, wears a sorrowful expression. Alongside the glittering fireworks, the image delicately captures the emotional turbulence of the two characters.
In addition, a teaser trailer has been released, featuring the voices of Makoto and Aki as performed by Sato and Hara. The footage includes glimpses of the fireworks painting that connects the two across 81 years, as well as scenes hinting at the beginning of their story, further heightening anticipation for what lies ahead. What, then, is the “promise” that binds them together?
For more details, including production credits and visuals, please check the official website.
Comments
Shori Sato
“I’ve always wished to work in animation. I held onto that desire for a long time, so when I received this offer, I was truly happy.
I’m also incredibly grateful to the entire production team for warmly welcoming me despite this being my first challenge as a voice actor. I hope to repay that kindness by honestly breathing life into Makoto’s voice. And someday, I’d really like to go see the Nagaoka fireworks in person. War must never be repeated. From the bottom of my heart, I wish for true peace to continue.”
Nanoka Hara
“After reading the script, I strongly felt the prayers embedded in the Nagaoka fireworks and the depth of the emotions carried by the people who have borne them through time.
While it is a story filled with the sparkle of youth and the excitement of a fateful meeting between two people, I also believe this work serves as a bridge that carries forward the powerful wish of past generations—’never repeat war’—to the next generation.
I will approach the upcoming recording sessions with care and sincerity, so that these feelings reach the hearts of everyone who watches the film.”
Original author Kaori Mado
“To think that a story I began writing without even knowing which publisher would take it on would one day become an animated feature film fills me with immense gratitude. The Nagaoka fireworks are a very special fireworks festival—when you watch them, tears somehow begin to fall. As I learned about the prayers and wishes embedded in the Nagaoka fireworks, a story came to mind about one boy and two girls living with all their might in the present.”
“The radiance that boys and girls display as they earnestly live each day is as beautiful and precious as fireworks. If audiences feel something in the theater as they watch an ordinary, unremarkable 15-year-old boy run forward relentlessly, weaving together not only the past and present but also the future, there would be no greater joy for me.”
“During the writing process, I happened to see Shori Sato on television, and I personally felt that his expressions and gestures overlapped with my image of Makoto. That he would actually play the role feels like a dream. Likewise, hearing Nanoka Hara’s voice, I can’t help but feel Aki in it—perhaps not just the author’s imagination. I trust Director Suzuki and am sincerely looking forward to the completed film.”
Character concept artist Akamoku
“Creating the character concepts is a crucial role that influences both the film and the novel. Because of that, I spent the most time repeatedly reading the original work and script, carefully engaging with Kaori Mado’s vision of each character’s personality and her interpretation of the Nagaoka fireworks.”
“While focusing on how my illustrations could best visualize her interpretation, and keeping in mind that this was a project intended for animation, I refined the designs to prioritize ease of movement and essential elements. By considering expressions, hairstyles, body types, and clothing designs as a whole, I aimed to create forms that truly conveyed each character’s individuality.”
“While I eagerly await the film’s completion, trusting all the studios involved, the novel version—illustrated after the character concepts were completed—also contains captivating scenes where you can feel a different version of Makoto and Aki than in the film. If you feel inclined, I would be delighted if you picked it up.”
Producer Michihiko Umezawa
“The year 2025 marked the 80th anniversary of the end of the war. The idea of creating a project to prevent the previous war from fading from memory first came to me in 2017. By chance, I went to see the Nagaoka fireworks, and that was when I learned they carry prayers for the souls of those who lost their lives in air raids and for the reconstruction of a Nagaoka that had been reduced to ashes.”
“I wanted to turn this into a film, so I approached the original author, Kaori Mado, and asked whether she would consider writing the story. She graciously accepted. Although it took many years—including the period of the COVID-19 pandemic—we are finally able to announce it, which makes me truly happy.
“I hope viewers, especially those close in age to the protagonists, will compare the restrictive era in which people could not freely express their thoughts with the freedoms of today, and find inspiration to live positively toward the future, just like Makoto and Aki.”
“Lastly, I would like to express my heartfelt gratitude to Shori Sato, Nanoka Hara, the director, the staff, and everyone who supported and believed in this project.”