Magical Girl Raising Project, Vol. 1 (manga)

The hit social network game "The
Magical Girl Raising Project" selects one out of every tens of thousands of
players to become a real life magical girl. The lucky chosen girls gain magic
powers as well as incredibly good fortune, and spend their days
blissfully.
But one day, an
absolute announcement declares that the number of magical girls has risen too
high and must be cut down to half. Sixteen young maidens are thrust into a
merciless, deadly contest to survive...but how many will come out the other
side?