Nyctophilia {Mikayuu}

Nyctophilia: (n.) Love of darkness or night; Finding relaxation or comfort in darkness.

Sixteen year old Yuichiro Amane hasn't had a family since he was three. He's been stuck in an orphanage ever since his parents mysteriously died. Not only does he not have a family, but he also doesn't have any friends. His obsession with darkness and night makes him a freak to others. Not only that, but his ramblings to the "air" makes him seem like he needs help to the other kids.
He's become fine with the silence and the rejection of other people. He has the shadowy like people that began coming to him and talking to him since he was six. He expects to never be adopted, have friends, or anything normal. That is until Mikaela Shindō appears in his life. He becomes fascinated by the nice, quirky, blonde that seemed to appear out of nowhere. He expects the blonde to be weirded out by his nyctophiliac traits but is surprised that the blonde accepts it without question and he reveals he's actually curious about it.
Yuichiro expects it's just harmless curiously, but has no idea that it's a lot more than that.