Brynhildr in the DarknessBrynhildr in the Darkness.

Brynhildr in the Darkness (Japanese: 極黒のブリュンヒルデ, Hepburn: Gokukoku no Buryunhirude; lit. 'Extreme-Black Brynhildr') is a Japanese manga series written and illustrated by Lynn Okamoto. It was serialized in Shueisha's seinen manga magazine Weekly Young Jump from January 2012 to March 2016, with its chapters collected in 18 tankōbon volumes. The series follows Ryouta Murakami, a young boy obsessed with proving that aliens exist, who sees someone that looks just like his deceased girlfriend.