Born in Amami Ōshima, Japan, she began to sing traditional Japanese music when she was four years old.
Rikki sang the Final Fantasy X main theme, "Suteki da ne", released as a single on July 18, 2001.
The single also included an instrumental version of "Suteki Da Ne", "Pure Heart" (a vocal arrangement of Aeris' Theme from Final Fantasy VII), and a new song entitled "Tsukisama" (which means 'The Moon').
[1] In 2001, she produced an image album alongside Joe Hisaishi for the motion picture Spirited Away (directed by Hayao Miyazaki).
She was involved in Sound Horizon's releases until 2008, when she gave birth to twins and returned to Amami Ōshima, as she said in her blog.