Lee Dain was born on August 14, 2008, in Gangneung, a coastal city in Gangwon Province, South Korea. Growing up near the sea, she developed an early familiarity with performing, beginning her entertainment career at a remarkably young age. On November 17, 2017, at just nine years old, Dain debuted as "U.Ha" in the kid group U.SSO Girl with their digital single "Go Go Sing." Among her groupmates was Lee Hyein, who would later debut with NewJeans under HYBE.

During her time with U.SSO Girl, Dain gained foundational experience in singing and dancing while also pursuing acting. In 2018, she appeared in several Korean dramas including tvN's "A Korean Odyssey" and SBS's "Secret Mother," showcasing her versatility as a young performer. That same year, while still active in entertainment, YG Entertainment reached out to her parents via direct message. At age 11, she auditioned and was accepted as a YG trainee, leaving U.SSO Girl to begin what would become six years of intensive training.

When Dain first joined YG Entertainment in mid-2018, she had minimal formal dance training despite her kid group experience. According to dance instructor Leejung Lee, who worked with BABYMONSTER trainees, Rora became "the trainee who has improved the most in dancing during the two years" of training.1 This dramatic improvement caught the attention of YG founder Yang Hyun-suk, who praised her ability to maintain an innocent appearance while delivering strong hip-hop dance performance—a rare combination he noted was difficult to find.

Impressed by her potential, Yang Hyun-suk personally selected her stage name "Rora," derived from "aurora" or the Northern Lights. According to official statements, he believed she could become an artist who shines as brightly as an aurora if her natural beauty and talent were properly developed.2 The name reflects YG's vision for her artistic identity—ethereal yet powerful, innocent yet commanding.

Between March and May 2023, YG Entertainment aired "Last Evaluation," a reality series documenting the final seven trainees competing for debut positions in BABYMONSTER. Throughout the series, Rora demonstrated consistent vocal ability, with Yang Hyun-suk praising her emotional expression during a September 2020 evaluation: "In my opinion, your vocals deserve 100 points considering your age. The way you express the emotions is great."3

When final rankings were announced, Rora placed sixth alongside fellow trainee Asa at seventh, initially putting both at risk of elimination. Yang Hyun-suk had originally planned to debut a smaller group. However, overwhelming fan support calling for all seven members to debut led him to reverse his decision. On January 30, 2023, Rora was officially introduced as the fifth member revealed to the public through a live performance video that garnered 9.7 million views within one week.4

BABYMONSTER debuted on November 27, 2023, with the digital single "Batter Up," though the group's official debut date is listed as April 1, 2024, to account for member Ahyeon's return. As lead vocalist and visual, Rora occupies a central position in the group's sound and image. Her warm, emotional vocal tone handles lower register sections and occasional high notes, while her presence as one of two designated visuals (alongside Pharita) contributes to the group's aesthetic identity.

Beyond her performance roles, Rora serves as BABYMONSTER's unofficial spokesperson, frequently taking the lead during interviews and song introductions. This communication responsibility leverages her articulate speaking style and comfortable stage presence, making her a key figure in the group's public interactions.

On November 30, 2024, BABYMONSTER and NewJeans appeared together on a Japanese broadcast, marking a reunion between Rora and Hyein six years after their U.SSO Girl days. At a subsequent Japanese fansign event, when asked if she had spoken with Hyein, Rora responded warmly: "It had been so long since we last met, but we were so happy—so happy that we hugged each other."3

From kid idol at age nine to lead vocalist in one of K-pop's most anticipated fourth-generation groups, Rora's journey exemplifies both natural talent and dedicated improvement. Her evolution from a trainee with limited dance experience to a performer praised for dramatic growth demonstrates the intensive training system that defines YG Entertainment. As she stated in her introduction video: "I want to be the first Rora rather than be the 'next' someone else. I want to be an artist who shines on stage like a beautiful aurora."