[4] Instead, Soyou auditioned for Starship Entertainment, singing a cover of Navi's "On The Road", and after her traineeship, she debuted as a member of Sistar in June 2010.

[10] She also collaborated with fellow label mates, K.Will and Boyfriend's Jeongmin, for Starship Planet's yearly holiday release, titled "White Love".

[17] The group performed their most successful summer hits – "Touch My Body", "Shake It", "Loving U", "I Swear" and also their last song "Lonely" on four major music shows, before concluding the schedule on Inkigayo on June 4, 2017 and officially disbanding.

[25] On December 13, Soyou released the first part of her solo album titled Re:Born with the single "The Night" featuring rapper duo Geeks and produced by Primary.

"[36] In September 2018, Soyou became the public relations ambassador for the Seoul branch of the Korean Red Cross, appointed by its Chairman.

She has been supporting the Seoul branch since 2015, aiding underprivileged groups like undernourished children, child-headed households, elderly individuals living alone, and multicultural families.

[37] In September 2014, Soyou collaborated with the "비커즈 (bcuz)" brand, known for its "wrap jeans," a popular fashion item at the time.

[39] In June 2015, Soyou teamed up with Sung Si-kyung as endorsers for CJ CheilJedang's 'Bibigo Wanggyoja,' a side dish ideal for pairing with beer.

[41] In the following years, Soyou continued promoting the brand, later adding their anti-aging supplement products to her list of endorsements, before parting ways at the end of 2021.

As part of the promotion, she released the single "Blue Nights of Jeju Island" alongside commercials and remained an active endorser until 2019.

[43] In September 2018, she participated as an endorser in Lotte Rental's summer vacation season exhibition for their lifestyle platform "MYOMEE."

On the same day, the organization revealed that she had been a part of the "Philanthropy and Culture Committee" of the Seoul branch since 2015, a group composed solely of high-value donors.

[52] In the following year, she was recognized as part of their 'Seoul Red Cross Pine Tree Club,' which is composed of individuals with cumulative donations totaling more than ₩30 million won.

[54] In April 2019, she donated ₩10 million won through the Hope Bridge National Disaster Relief Association, requesting that it be used to aid residents affected by large-scale forest fires in Gangwon-do.

[55] In February 2020, Soyou donated ₩20 million won through Good Neighbors, an international relief and development NGO, to help prevent COVID-19 among Daegu residents.

[57] Later in November, she donated a total of ₩20 million in scholarships to twenty underprivileged university students in Seoul through the Korean Red Cross Society for which Soyou acts as a public relations ambassador.