Mahou Shoujo Ikusei Keikaku: limited

During an ordinary after-school club gathering, a tiny fairy named Toko unexpectedly arrives and informs the seven present students that they are capable of becoming magical girls. In return for granting them these powers, the girls agree to help rescue Toko from a group of mages pursuing her. However, the girls soon realize the threat is more dangerous than anticipated, as the mages themselves possess magical girl abilities.