Black★Rock Shooter is a franchise that revolves around a mysterious black-haired girl with a blue glowing eye. She shoots black rocks, among other things.
The Black★Rock Shooter franchise started out as an illustration by Huke, grew into a song by Supercell, and ended up spawning a 50-minute OVA, 3 manga series, a short anime series, and multiple games.
All the entries in the franchise are centered around a mysterious girl with a glowing eye and a big cannon capable of shooting rocks at high-speed, with some other characters also appearing in some of the adaptations.
For more information, see:
- Black Rock Shooter on Wikipedia