On March 2, Starship Entertainment confirmed with various media outlets, "It's true that Lee Hyori participated in Soyu's comeback song. Soyu is currently preparing to return solo with a new album in mid-March."
According to reports, Lee Hyori took part in Soyu's comeback song both as a composer and producer, working with the solo artist for the first time. Last year, Lee Hyori also worked actively as a producer by working with Koyote, Babylon, etc.
Stay tuned for even more details on Soyu's March comeback!
[Update: Official teaser image]