YU-KI is a Japanese singer-songwriter who rose to fame as the vocalist of the rock band Judy and Mary. After the band's disbandment in 2001, she embarked on a successful solo career, releasing numerous hit singles and albums. YU-KI's music is known for its emotional depth, soaring melodies, and introspective lyrics, which often explore themes of love, loss, and self-discovery. She has collaborated with various artists, including L'Arc-en-Ciel's Hyde and Glay's Takuro, and has contributed songs to popular anime and drama series.