The film will open in Japanese theaters on April 15. The film will be a love story set in Osaka, and it will feature Heiji Hattori and Kazuha Toyama. The visual (pictured at right) shows Momiji Ōoka, a high school karuta champion who refers to Heiji as her future husband and is a romantic rival for Kazuha. She appears in the manga for the first time in the 91st compiled volume, which shipped on December 16 in Japan, and this will be her first anime appearance. Satsuki Yukino voices the character.Daisuke Ono will play Muga Iori, a butler to Momiji's family. The character has already appeared in the manga but will also make his anime debut in the film. The following cast members from the television anime are confirmed for the film: Minami Takayama as Conan Edogawa, Wakana Yamazaki as Ran Mōri, Rikiya Koyama as Kogorō Mōri, Ryo Horikawa as Heiji Hattori, and Yuko Miyamura as Kazuha Toyama.
Kobun Shizuno, the director of the last six Detective Conan films, is returning to direct the film at TMS and V1 Studio. Takeharu Sakurai is also returning from earlier films to write the script based on Aoyama's story, and franchise composer Katsuo Ono is again providing the music.
The 20th film, Detective Conan: The Darkest Nightmare, opened in Japan last April, and set a record high for the film franchise at the box office.