Brynhildr in the Darkness

As a child, Murakami shared a deep bond with a girl known as Kuroneko. Tragically, she dies in an accident while attempting to convince him of the existence of aliens, an event that leaves Murakami haunted by guilt. Determined to honor her memory, he devotes his life to uncovering extraterrestrial truths. His quest takes an unexpected turn when a new classmate, Kuroha Neko, arrives. Mysterious and strikingly similar to Kuroneko, she possesses extraordinary abilities that reignite Murakami's quest and blur the lines between his past and present.