Huke

It isn't the world you know. There wanders a girl with jet-black hair, ebony clothes, and a strikingly blue, glowing eye. Her name is Black-Rock Shooter. With a huge cannon in hand, she throws herself into a fierce battle... Meanwhile, in another world, middle-school student Mato Kuroi is drawn to Yomi Takanashi, her classmate with an unusual family name. Mato does her best to talk to Yomi, who just won't open up. (myanimelist.net)