坂井泉水

Sachiko Kamachi , known professionally as Izumi Sakai , was a Japanese pop singer and core member of the group Zard. As Sakai was the only member in the group for the majority of the 16 years which it was active, Zard and Sakai may be referred to interchangeably. She was the best-selling female recording artist of the 1990s and has sold over 38 million copies of sales, making her one of the best-selling music artists in Japan of all time.