The events of the film are set in modern-day Japan and star Aoi Morikawa, Rena Matsui, and Momoiro Clover Z member Kanako Momota in the roles of three women of different backgrounds who grew up watching Ojamajo Doremi.

Aiming for an adult female audience outside of Ojamajo Doremi fans, Toei Animation decided to focus on the various common struggles that Japanese women face in their daily lives, with each main character representing a particular generation.

The film is centered on three women who grew up watching Ojamajo Doremi in their childhood: Sora Nagase, a 22-year-old college student whose parents are pressuring her to become a teacher; Mire Yoshizuki, a 27-year-old career-oriented office worker returning from overseas; and Reika Kawatani, a 20-year-old freeter.

[3] Sora is concerned about Yūji Makita, a student with a learning disability at the school she interns at; despite having her dream job, Mire feels disrespected by her managers; and Reika's boyfriend, Seiya Kubo, keeps stealing her savings for college.

[2]: 5  One day, Sora becomes curious when she hears rumors about a Western-style building located in Kamakura that served as the basis for the MAHODO, a magic shop featured in Ojamajo Doremi.

[2]: 6  At night, while discussing concerns from their daily lives, Reika confides in them that her father left after her parents divorced when she was in high school, with her mother dying two years later.

While on the train, the women befriend Ryuichi Omiya, a college student, and after noticing he has a keyholder of Onpu, they discover he is also a fan of Ojamajo Doremi and he comes along their trip as their guide.

Three months after their trip, Sora, Mire, and Reika rent the building in Kamakura to open it under the name Café MAHODO as the culmination of all their dreams combined.

They see a silhouette running in the halls in the process, and after giving chase, they find Doremi, Hazuki, Aiko, Onpu, Momoko, and Pop.

[11] On October 29, 2019, the production team revealed at the 32nd Tokyo International Film Festival that the film would be titled Looking for Magical Doremi and its story details, as well as announcing that staff members who worked on Ojamajo Doremi would be returning for the project, including director Junichi Sato, scriptwriter Takashi Yamada (credited under the pseudonym Midori Kuriyama),[2]: 134  character designer Yoshihiko Umakoshi, and producer Hiromi Seki.

[2]: 129  Sato was initially going to have the film centered on Doremi and the other main characters of the original anime as adults, with a "miracle" happening through a time paradox.

[2]: 129 [13] After agreeing to focus on a general audience instead of only Ojamajo Doremi fans, the staff created Sora, Mire, and Reika as the main characters with varying ages to show their generational differences.

[13] For Ojamajo Doremi, instead of using "light and cute" backgrounds that were expected for children's television shows, Sato opted to use "heavier tones" of color to create a more "mature taste" that would "bring more depth to the world.

[16] In February 2020, Toei announced that the starring cast consisted of Aoi Morikawa as Sora Nagase, Rena Matsui as Mire Yoshizuki, and Momoiro Clover Z member Kanako Momota as Reika Kawatani.

[17] Hiromi Seki had personally sent a letter to Morikawa after seeing her acting in the live-action television drama adaptation of Kakafukaka and envisioned Sora to be like the character she portrayed.

[2]: 15  Likewise, Miura, who had also watched Ojamajo Doremi when he was young, mentioned the film's announcement on social media and his radio show, after which he later heard he had received an offer.

[4]: 2 In addition to the film cast, Chiemi Chiba, Tomoko Akiya, Yuki Matsuoka, Rumi Shishido, Nami Miyahara, and Sawa Ishige reprise their roles as Doremi Harukaze, Hazuki Fujiwara, Aiko Seno, Onpu Segawa, Momoko Asuka, and Pop Harukaze from the Ojamajo Doremi anime series.

(Majo Minarai o Sagashite Version)" by MAHODO (Chiemi Chiba, Tomoko Akiya, Yuki Matsuoka, Rumi Shishido and Nami Miyahara), featuring a new arrangement.

[28] To promote the film, Looking for Magical Doremi collaborated with various fashion and character brands, such as The Kiss,[29] Ichiban Kuji,[30] Sanrio,[31] and Earth Music & Ecology.