Black Rock Shooter project . According to information, the production is called Black Rock Shooter: DAWN FALL . Official Website .
Synopsis:
Kuroi Mato is a new student and on the first day of class, she meets Takanashi Yomi. Although they seem like extreme opposites, a friendship between the two blossoms as time passes. But, as the second year of high school passes, they are in different classes and begin to grow up separately.
Therefore, the work began with an illustration of the character on pixiv in December 2007 by illustrator Huke. The illustration inspired a song with the same title using Hatsune Miku , and later spawned an OVA in 2010 and an anime in 2012.