is a Japanese pop singer and actress. She was born in Fukuoka, Fukuoka Prefecture, Japan. She married Yūichi Takasō in 1998, and divorced on July 31, 2010. She and Yūichi have one son, born in 1999. She is particularly popular in Hong Kong and Taiwan. Her best-selling single to date is Aoi Usagi (碧いうさぎ?, "blue rabbit").
Sakai released her debut single, "Otoko no Ko ni Naritai" (男のコになりたい?, "I Want to Be a Boy") on February 5, 1987, nine days short of her sixteenth birthday. Over 40,000 copies of the single were sold. In the early years of her career, she used the nickname Nori-P (のりピー?), although around the mid-1990s she started to distance herself from it.
Sakai recently re-emerged in the headlines again for a drug scandal in August 2009, where she received a three-year suspended sentence for drug abuse.