Meitantei Conan Kara Kurenai no Love Letter's opened in Japanese theaters on April 15. The film sold 987,568 tickets and earned 1,286,928,000 yen (about US$11.88 million) in its opening weekend setting a new opening weekend record for the franchise. The film also topped the Japanese weekend box office chart.
The film is a love story set in Osaka, and features Heiji Hattori and Kazuha Toyama. The visual (pictured at left) 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 film was her first anime appearance. Satsuki Yukino voiced the character.
Kobun Shizuno, the director of the last six Detective Conan films, returned to direct the film at TMS and V1 Studio. Takeharu Sakurai also returned from earlier films to write the script based on Aoyama's story, and franchise composer Katsuo Ono again provided the music.
The following cast members from the television anime returned for the film: Minami Takayama as Conan Edogawa, Wakana Yamazaki as Ran Mōri, Rikiya Koyama as Kogorō Mōri, Ryo Horikawa as Heiji Hattori, Yuko Miyamura as Kazuha Toyama, and Daisuke Ono as Muga Iori.
The 20th film, Detective Conan: The Darkest Nightmare, opened in Japan in April 2016, and set a record high for the film franchise at the box office at the time.