Kiroro are actually two girls from Okinawa. Kinjo Ayano and Tamashiro Chiharu. They're quite popular in Japan and they've been releasing material since 1998, i believe.
Here's their official website: dfltweb1.onamae.com – このドメインはお名前.comで取得されています。
It's completely in Japanese though. I don't know of any English fansites.