[2] Sunmi revealed on a 2018 episode of Talkmon that she first decided to become a celebrity when she was 12 after her father was admitted to hospital due to complications of pulmonary tuberculosis.

She was inspired by BoA, who debuted at the age of 13, and it was for her "the fastest way to make money" in order to take care of her mother and two younger brothers.

In January 2010, JYP announced that Sunmi would be postponing her musical career to pursue her studies, but would continue until February in order to complete scheduled events.

[12] On June 24, 2015, JYP Entertainment announced that Sunmi would be re-joining Wonder Girls, after withdrawing in 2010, for their comeback after the group's two-year hiatus.

[30] On February 6, 2020, Sunmi released the single "Gotta Go" along with its instrumental as part of the original sound track of the web series XX in which she made a cameo.

[35][36] On July 22, she was selected as the exclusive model of 요괴미식가 (the Korean version of Yokai Kitchen) created by FriendTimes; in the TV commercial of the game, she played a gourmet who enjoyed cooking in the mysterious spirit realm restaurant.

[42] The single was released as part of a collaboration with DWG KIA, a League of Legends esports team who won the 2020 World Championship.

[49] Later in the year, in an interview for 1TheK's YouTube channel published in September 2018, she revealed that her personal goal was to create her own music style named after herself.

[51] One week ahead of the release of her single "Noir", she mentioned her main goal during a detailed interview for Billboard Korea, hoping that her musical style would become something that could inspire other artists.

Even though the tweet itself didn't mention the term, Korean media and industry players started to officially recognize the word "Sunmi-pop" and implement it in articles and variety shows for the first time to describe Sunmi's music, reporting that she created her own style by applying her abilities in self-writing, self-composing and ideating performances.

[46][54] On May 30, 2019, in London, right before going up on the stage of the Warning World Tour, an interviewer of the Korean media agency Yonhap News made known to Sunmi that a term to describe her musical style had been coined already as "Sunmi-pop".

[57][58] "Sunmi-pop" songs feature upbeat dance rhythms with lyrics marked by metaphors and double meanings that slightly conceal a sense of cynicism.

[61] Additionally, the songs "Gashina", "Heroine", "Siren", "Black Pearl", "Curve", "Lalalay" and "Tail" all present metaphors in the lyrics thus defining Sunmi's style of expression.

[59] Although "Sunmi-pop" songs mostly present an exciting and happy beat, Sunmi shared that her lyrics are often imbued with a sense of cynicism due to the fact that, in her real life, as a celebrity, she can't always express her true feelings.

Park wanted her and the other members to "broaden [their] understanding of the different music styles of different eras" focusing especially on retro concepts and Motown artists, which she ended up liking.

[52] On the April 2021 issue of L'Officiel Singapore, Sunmi explained: "I always try to come up with fun and easy ways to approach a range of people, while keeping the original emotions in myself".

[48] Another key element of "Sunmi-pop" is dynamism: Sunmi shared her wish of wanting to try new ideas every time, like working with other producers, and explore new genres by showing a different range of themes, aesthetics and sounds through the years.