Kira Kira メロディ学園 (Melody Gakuen) is the name of the anime and game featuring many girls who want to become idol seiyuu (and actresses and singers). It is also the name of the virtual school of the young seiyuu who are doing the roles of the girls. So there is a crossover between the virtual girls and the real girls.
The anime and game didn't come out, but the Kira Kira Melody Gakuen project ended on 2001.03.25. Students (First class) Groups Audio drama Students (Second class)
CDs
What is Kira Kira Melody Gakuen?
The Kira Kira Melody Gakuen project started in spring of 1999 with over 50 girls in the First Class. Then in spring of 2000, there were 50 new girls chosen for the Second Class. 2 Gakki (video) PV Shuu 3 Gakki (video) Final Live (video) Stand Up (official mook) Telephone cards Paper Crafts Badges Radio (Ani Game Paradise) Events [HD's event reports] 1999 2000 2001
Source: http://www.usagi.org/doi/kkm/