Set in Ikebukuro, the film follows Mio Miyamasu (Matsumoto), a high school girl who tries to reconcile with her childhood friend Arata Kirishimo (Seto), following their argument when she gets involved in a traffic accident that transports her to a new world.

After her markup exam, Mio is approached by her best friend Madoka and learns that she also likes Arata, causing uneasiness since she has trouble admitting her feelings.

In March 2020, Toho announced the production of an original "adolescent fantasy" anime film titled Kimi wa Kanata (lit.

To create an atmosphere where their characters "might become lovers" in the film, Matsumoto and Seto performed in a setting where they were dating at a museum, with Sena playing as a "strange uncle".

[4] Additional cast of the film were announced in August 2020, including Saori Hayami as Kiku-chan, Yui Ogura as Madoka, and Koichi Yamadera and Ikue Ōtani as Gimon.

[17][18] Mari Natsuki, Naoto Takenaka, Anna Tsuchiya, Nobuko Sendō, and Takehiro Kimoto also joined the cast to respectively voice Mrs. Mori, Mogari, Orika, Sachi Miyamasu, and a lost-and-found officer in October 2020.

[19] The film's novelization written by Sena and illustrated by Tomoyuki Abe was released by Kadokawa under their Fujimi Fantasia Bunko imprint in Japan on November 20, 2020.

[24] Promotional partners for the film included Animate Cafe,[25] Seibu Railway,[26] and Crossdine Cake Shop in Tokyo's Hotel Metropolitan.

[31] Crunchyroll began streaming the film in the United States, Canada, Australia, New Zealand, South Africa, Netherlands, Denmark, Finland, Norway, Sweden, and Iceland on October 21, 2021,[32] while HBO Max released it with Portuguese and Spanish dubbing in the Latin America region on April 4, 2022.

[36] Allen Moody of THEM Anime Reviews gave Over the Sky 3 out of 5 stars, feeling that the film was a "smorgasbord of repurposed stuff from other shows" like Fireworks (2017), Mirai (2018), Weathering with You (2019), and the Frozen franchise.