About Heo Sol-ji
Heo Sol-ji, known mononymously as Solji, is a South Korean singer. She was a member of the ballad duo group 2NB from 2006 to 2010. She later became a vocal trainer before joining EXID in July 2012 as the leader and main vocalist. In February 2015, Solji participated in a singing competition program, MBC's King of Mask Singer, for their pilot episode, in which she won the title. She appeared as Self-Luminous Mosaic and defeated singer and comedian, Shin Bora, and trot singer, Hong Jin-young, and became the first winner of the show, impressing the panel of judges as well as viewers. In the end, Solji and Doo Jin-soo won with a score of 477, which is still the highest score in the episode, and impressed the judges and the viewers yet again.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.