Yukimi Nagano

Follow her voice through delicious groups, starting with Hird - listen to "Keep you Kimi," the song that made me fall for her.
Little Dragon - "Twice" and "After the Rain"
Koop - "Come to Me"

These are just the tracks I could find that you can stream, but I recommend anything she guests on. The Hird album, the Koop albums, and Little Dragon. Check out an interview here.