Born in Kishiwada City, Osaka, Nagai Miyuki won the grand prize at the 6th Kansai Enka Awards in 1988. In the following year, she moved to Tokyo and became an apprentice of Takashi Taka, a prominent lyricist. In 1992, Nagai debuted as an enka singer with a single “Osaka Suzume” from Sony Records at the age of 16. She attracted much attention and high praise for her cute looks and clear voice. The same year, she was awarded the New Artist Award for the enka division at the 34th Japan Record Award. She continued on singing while she was a college student and stayed active as an enka idol. She took a new challenge of hosting a nationwide radio show in October 2000 until the following year. After changing her label to Teichiku Records in 2001, she joined a unit “Rainbow Usagi-gumi” with Kaori Uesugi and Hiromi Yamaguchi, in which all three members were born in the year of rabbit(=usagi). When she made an announcement at an event for the release of her new song in 2010, she described herself as “the Sky Tree of enka” as she was still growing just like the way Sky Tree was being built taller by day.