Son Hye-ju (Hangul: 손혜주; born on November 13, 2001 in Seoul, South Korea) known mononymously as HyeJu (Hangul: 혜주), and formerly known as Olivia Hye (Hangul: 올리비아 혜), is a South Korean singer, rapper, and dancer. She is the twelfth and last revealed member of LOONA and a member of its third sub-unit, LOONA / yyxy. She is also a member of Loossemble. She debuted on March 17, 2018 as a member of LOONA and subsequently released her solo single album "Olivia Hye" on March 30, 2018.