Mio Isayama (諫山実生), born on June 8, 1980, is a J-pop musician who debuted in August 2002 with the single "Koi Hanabi" (恋花火). which was featured on NHK's Minna no Uta (みんなのうた).
Her only big commercial hit was another Minna no Uta song, "Tsuki no Waltz" (月のワルツ), in December 2004, but despite her relatively obscure status she has managed to remain on the major label TOSHIBA EMI throughout her career, and continues to release an average of 1 album and 2 or 3 singles each year.
Since then she has released a total of 17 singles (including 2 digital-only singles) and 8 albums. Her newest, the album "Legato", was released on February 2, 2011.