Gokukoku no Brynhildr

Japanese Title: 極黒のブリュンヒルデ

English Title: Brynhildr in the Darkness

Chinese Title: 極黑的布倫希爾德

Plot
When he was a child, Ryouta Murakami was infatuated with a girl he called Kuroneko. She insisted on knowing about aliens and having met them, but no one believed her, even young Murakami was skeptical. One day, she decides to show him the aliens, but an accident occurs and Kuroneko dies while Murakami is left seriously wounded in the hospital.

Years go by and Murakami obsesses on finding proof of the existence of aliens because of a promise he had made with Kuroneko. He has continuously looked up at the sky as a member of the astronomy club. Then, one day, a new transfer student comes to his class, who not only looks a lot like Kuroneko, but is named Neko Kuroha! She displays supernatural strength when saving Ryouta from a foreseen accident. It turns out that she is a magic-user that has run away from a research lab. From then on Ryouta supports these magic users, hoping to live normal lives regardless of being pursued. How will Ryouta's life change now?