Kim Yong-sun, better known by the stage name Solar, is a South Korean singer, songwriter, and actress signed under RBW. She is the leader and vocalist of girl group Mamamoo and its sub-unit Mamamoo+. She made her solo debut with the single "Spit It Out" on April 23, 2020. She released her first extended play 容: Face with its lead single "Honey" on March 16, 2022. Solar ventured into musical acting through the musical Mata Hari for its 2022 production on May 28, 2022, marking her first role as a musical actress.