She was influenced at an early age by Whitney Houston's singing and Michael Jackson's dancing. In her second year of junior high school, she submitted a demo tape to the GIZA recording label and won a contract. She debuted in the United States in 1999 with the song "Baby I Like," recorded under the pseudonym Mai K. Her first Japanese single, "Love, Day After Tomorrow," was released later in the year. It became a big hit in Japan and sold about a million copies. Kuraki now holds the record of having all 27 of her singles in the top-ten since her debut according to the Oricon's female artists ranking record.

Kuraki's career has been somewhat overshadowed by that of her slightly younger contemporary, Utada Hikaru. Despite this, Kuraki's album Delicious Way sold more than 3 million copies and became the best selling album of 2000 in Japan, cementing her status with singers like Ayumi Hamasaki and Utada Hikaru. Her second album, Perfect Crime, sold more than 1 million copies in 2001. Her all-African-American tour band, Experience, is also somewhat prolific. They were featured in the music video for "Stand Up", and released one single featuring Kuraki Mai's vocals and a Michael Jackson tribute album. Her English-language ventures, the single Baby I Like and the album Secret of My Heart were both major flops, even though they were the flagship releases of the GIZA USA label. Year 2002 was a year of success for Kuraki Mai. January that year, "Winter Bells," the 10th opening theme for the popular anime Detective Conan, reached the top position of the Oricon charts. FT Shiseido chose "Feel fine!" as the theme song for its 100 year celebration campaign. The single release of the song briefly held the daily top spot against Ayumi Hamasaki's "Free & Easy", but lost out the weekly top spot.