Sojin wrote the intro song "Girl's Day World", and co-wrote the lyrics for "I Don't Mind" with her fellow members.

[citation needed] 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".

[citation needed] On June 24, 2020, So-jin has confirmed her appearance in MBC's 'The Spies Who Loved Me', which will be aired in October.

[9] On June 17, 2022, So-jin cast as the one act-drama Don't Announce Your Husband's Death as role Yoo Young-joo.

[10] On October 6, 2023, Sojin announced on her fan cafe that she will marry actor Lee Dong-ha [ko] in November 2023.