Giddens Ko originally pitched to adapt Precisely Out of Control into a feature film for 21st Century Fox, the proposal was scrapped due to the company's acquisition.

Ko revived the project while producing Bad Education (2022), choosing to adapt only the fourth chapter of the novel with Machi Xcelsior Studios, following their collaboration on Till We Meet Again (2021).

He manages to locate the Thai assassins at a hotel where they stayed, but discovers that the owner Tung is actually a longtime acquaintance of Tai and had no involvement in the plot.

Frustrated by the lack of leads, Long Legs is angered by Tai's seemingly carefree attitude and disappointed with his apparent softness since meeting Fen.

Cheng later visits Fen's salon, explaining that Tai was his high school baseball team captain, expelled for protecting his teammates from harassment by thugs.

[13] Miss Shampoo is loosely based on the fourth chapter "This is the Feeling I Want" (Chinese: 這是我要的感覺) of Giddens Ko's 2010 novel Precisely Out of Control [zh].

[16] After joining Machi Xcelsior Studios, Lu selected and oversaw the production of Till We Meet Again (2021), another film adaptation of Ko's novel.

[18] Ko conceived the idea of adapting this novel while producing Bad Education (2022),[8] and the project marks his fourth feature film as a director.

[19] He described the story as triads-themed, emphasizing his desire to portray "the triad members as admirable through their experiences of falling in love".

[24][25] Singer Jeffrey Huang was initially cast in the lead role as Tai, prompting the production company to increase the film's budget due to his involvement.

[26][27] Giddens Ko envisioned the character as middle-aged and bilingual, returning from America to reclaim his position as a gang boss, to suit Huang's traits.

[28] However, Huang dropped out after taking acting classes, citing scheduling conflicts and a greater interest in another one of Ko's projects, Kung Fu, which was stalled in development.

[3] On 1 August 2022, Daniel Hong and Vivian Sung were confirmed as the lead cast, while other details about the film remained under wraps.

[16] The Mei-mun Hair Salon, a main set for the film, was designed and built in an empty shop located in Ximending, Taipei.

[22][40] Several local residents accidentally walked onto the production set during filming, mistaking the hair salon for an actual business.

[22] Ko initially explored bathhouses in Taipei during location scouting but found their interior design too modern and not reflective of the atmosphere he desired, so he chose to film in Taoyuan instead.

[54] The film's end credits included voice recordings of a conversation between Giddens Ko, Daniel Hong, and Vivian Sung discussing the choice of performer for the theme song.

[57][58] The song faced online backlash for its lyrics containing sexual innuendos, and the film's release coincided with the the resurgence of the #MeToo movement in Taiwan [zh],[a] prompting lead actor and composer Daniel Hong to publicly apologize.

[81] James Marsh of the South China Morning Post gave the film 3/5 stars, commenting that Miss Shampoo is a "giddily self-satisfied romantic comedy" that, while bursting with youthful energy and clever plotting, is ultimately undermined by a juvenile sense of humor, despite its charming leads and engaging premise.

Pryor of Cinapse focused on the writing and offered a positive review, praising the film as "raucous, laugh filled", expertly blending romantic comedy and crime elements, and highlighting Giddens Ko's improved ability to engage audiences with humor and "endearing" character dynamics.

[4] Estella Huang of Mirror Media criticized the film for closely resembling the story and character settings of the Korean film Man in Love (2014), and noting that its emphasis on humor over emotional depth undermines the seriousness of the central romance, resulting in a narrative that feels more like a variety show than a cohesive story.

[83] Berton Hsu, in his review for The News Lens, emphasized that "the box office was below expectations", finding that the chaotic blend of humor, dark themes, and romance elements, combined with a disjointed narrative filled with clichés, resulted in a lackluster adaptation.

News, lamented the film as "a work of failure", criticizing the clichéd romantic relationship between Tai and Fen, along with crude dialogue that are derogatory to women and noting that the male characters are rendered stereotypical, suggesting that Ko seems to be "stuck in his own parallel universe" in contrast to the rising #MeToo movement.

[86] Keith Ho, writing for HK01, also acknowledged that the film pays homage to Hong Kong cinema, effectively blending action and gangster elements typical of Hong Kong films with romance and drama, all while making significant changes to its source material, resulting in an entertaining and emotionally engaging experience.