Gokukoku no Brynhildr  

Brynhildr in the Darkness, 极黑的布伦希尔德, 極黒のブリュンヒルデ

Ten years ago, Ryouta Murakami and Kuroneko embarked on a mission to prove the existence of extraterrestrial life. However, during their journey, they encountered an accident that claimed Kuroneko's life and left Ryouta critically injured. Now, ten years later, Ryouta has recovered from his injuries and is attending high school as a normal student. Despite this setback, he remains determined to prove the existence of aliens in honor of his late friend. One day, Neko Kuroha, a transfer student who bears a striking resemblance to Kuroneko and shares her name, arrives at Ryouta's school. She also possesses supernatural powers, which piques Ryouta's interest. As he gets to know Neko better, Ryouta is drawn into a dangerous world where scientists hunt magic-wielding witches who have escaped from their secret research laboratory. Neko is one of these escapees, but there are many others in similar situations. It falls upon Ryouta to protect them from their would-be captors. Despite the challenges ahead, Ryouta remains committed to his mission and will stop at nothing to prove that aliens exist.

Gokukoku no Brynhildr adapts the first 10 volumes of Lynn Okamotos manga series of the same name.