Kim Ji-woo (Korean: 김지우; born October 20, 1999), better known as CHUU (Korean: 츄), is a South Korean singer under ATRP. She was the tenth revealed member of South Korean girl group LOONA, where she was a vocalist and rapper. She was also a member of the group's third subunit, LOONA/yyxy. She debuted as a member of LOONA with her solo single album Chuu on December 28, 2017, as part of the pre-debut "Girl of the Month" project under BlockBerry Creative. The single album included lead single "Heart Attack", and B-side track "Girl's Talk", a duet with member Yves. On November 25, 2022, BlockBerry Creative announced that CHUU had been expelled from LOONA, citing "reports of abuse of power, such as Chuu's abusive language towards staff". BlockBerry refused to provide evidence to support these claims, and several industry professionals publicly defended CHUU's character in light of her removal. As a result, many fans viewed her expulsion as unfair and unjust. Three days later, 9 of the 11 remaining LOONA members filed injunctions to suspend their exclusive contracts with BlockBerry Creative. In the following days, the company announced a comeback featuring the 11 remaining members. Outraged by the mistreatment of the group members and CHUU's removal, fans organized a boycott of the comeback, ultimately leading to the album's indefinite postponement. In the aftermath, all remaining members of LOONA successfully terminated their exclusive contracts with the company. Despite her removal from the group, fans, members, and CHUU herself still refer to her as a rightful member of LOONA. On April 7, 2023, CHUU signed an exclusive contract with ATRP. She released her first mini album Howl on October 18, 2023, featuring the title track as the lead single. On February 13, 2024, CHUU released the digital single "Chocolate" as a Valentine's Day gift. An English version of the song was released the next day. Both versions ended up on the tracklist of her second mini album Strawberry Rush, which was released on June 25, 2024, and included the lead single of the same name. On April 21, 2025, CHUU released her third mini album Only cry in the rain, alongside the lead single of the same name.