When does Black Rock Shooter: Dawn Fall return?

Black Rock Shooter is a Japanese media franchise based on characters created by illustrator Ryohei Fuke. It revolves around its eponymous character, a mysterious black haired girl with a blazing blue eye. The original illustration inspired a song of the same name by Supercell featuring the Vocaloid Hatsune Miku. A 50-minute original video animation based on the franchise was produced by Yutaka Yamamoto's studio Ordet. The franchise has also spawned several manga series and a video game for the PlayStation Portable.