Moon Byul, a member of MAMAMOO, is in charge of rap position and has been loved by the public for her neat rap performance and neutral charm since her debut. In May 2018, She released her first solo album, "SELFISH," showing off a different charm that was not easily seen. With her bouncy voice, she was imprinted as a versatile artist, performing not only rap but also vocals. In February 2020, about a year and nine months after the first album, she released her second solo album, "Dark Side of the Moon," which led her to a complete image transformation. She showed the unique aspect of a female solo artist by intense performance, rapping and vocals. Also, she held her first solo concert online and made great achievements with new attempts such as changing various stage effects, which are different from other online concerts.