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Before debut, Sojin worked as a vocal trainer for K-pop boy band Ulala Session.
On July 7, 2010, Sojin debuted as a member of Girl's Day on KBS' Music Bank with their debut single, Tilt My Head.
On January 9, 2011, Sojin released her first solo single for the Flames of Desire OST, "Our Love Like This".
On April 19, 2012, Girl's Day made a comeback with the mini album Everyday II. The album included the song "Telepathy", which was composed by Sojin. That same year, Sojin and a male composer wrote the song "It's Snowing" for Tokyo Girl. The song was released on December 7.
On March 14, 2013, Girl's Day released the full-length album Expectation. Sojin wrote the intro song "Girl's Day World," and co-wrote the lyrics for "I Don't Mind" with her fellow members. On October 15, Girl's Day released the song "Let's Go", written and composed by Sojin.
On March 2, 2014, Sojin collaborated with hip hop artist Crucial Star on a remake of Park Hye Kyung's song "Three Things I Want to Give You".
On January 30, 2015, Sojin lent her voice for "Dizzy Dizzy" for Part 2 of her starring SBS weekend drama 'The Family Is Coming' (Family Outing) OST.