Produced by Studio VOLN and distributed by Aniplex, the film is written and directed by Shinichiro Ushijima and stars Mahiro Takasugi, Lynn, Yukiyo Fujii, Yuma Uchida, Jun Fukushima, Atsuko Tanaka, Shin-ichiro Miki, and Emi Wakui.

In the film, an unnamed male high school student befriends his classmate Sakura Yamauchi, who is revealed to have a terminal illness in her pancreas.

The staff for the film were revealed in March 2018, with Takasugi and Lynn being announced as the unnamed male high school student and Sakura, respectively.

The film grossed over $6 million worldwide and received positive reviews from critics, who praised the story and its message, animation, and writing.

During their school break, Sakura invites him on a train trip to Fukuoka where they play truth-or-dare game and eventually share a bed in their hotel room.

[10] Additionally, Mahiro Takasugi and Lynn were announced to be starring in the film as the unnamed male high school student credited as "Me" (僕, Boku)[11] and Sakura Yamauchi, respectively.

[12] In June 2018, Yukiyo Fujii, Yuma Uchida, Jun Fukushima, Atsuko Tanaka, and Shin-ichiro Miki were cast as Kyoko, Takahiro, Gum Boy, and "Me"'s mother and father, respectively.

[5] In August 2018, 3DCG director Koremi Kishi stated how the team spent a lot of time and effort animating trams and diesel railcars since they were "important elements of the [film]'s worldview."

[5] The two theme music and the original soundtrack, which includes the film version of the insert song "Secret" (秘密, Himitsu),[18] were released in Japan on August 29, 2018.

[5] To My Father and to Someone in My Memories (父と追憶の誰かに, Chichi to Tsuioku no Dareka ni), a sequel to the light novel series, was announced in August 2018 as a gift to filmgoers in Japan who saw the film in participating theaters.

Chūbu travel agency,[28] Uniqlo,[29] Hakata Ikkousha ramen restaurant,[30] Sweets Paradise store,[31] Cerezo Osaka,[32] and Respect for Geeks (R4G) clothing brand.

[9] The film held its Australian premiere at the Madman Anime Festival in Melbourne in September 2018 and was widely released in the country on October 18.

[50] James Perkins of Starburst felt the film was a "devastatingly beautiful - a gut-punch of a romantic drama that will leave you broken and have you crying your eyes out by its ending with its respectful portrayal of dealing with and accepting loss and finding wonder in the world during the short time we are on this planet for."

[51] Alex Osborn gave the film 8 out of 10 for IGN Southeast Asia, feeling that it was "a beautiful and moving exploration of what it means to truly live".

Osborn praised the art direction and premise that it "isn't especially novel, but the strength of its core relationship and the satisfying way it concludes makes for a memorable story with a powerful message.

[53] Matt Schley rated the film 2 out of 5 stars for The Japan Times, feeling that it would "either leave you sniffling or wishing some zombies had shown up after all."