"If you love him, then use your monster's power."
Konoha is a kind young man who appears in Konoha no Sekai Jijou, trying to rescue Hibiya and Hiyori.
But Dark Konoha, who first appears in Children Record, is the exact opposite of Konoha in both appearance and personality. Konoha's hair and clothes are white, but Dark Konoha's are black, and his eyes and the mark on his right cheek are yellow. And the shot we see of him in profile in the PV shows him smirking. He may prove to be an important key to the story that we do not yet know.
He appears in Lost Time Memory as well, and he is portrayed crying and attempting suicide by shooting himself in the temple; Kisaragi Shintarou stops him.
The song Outer Science on Mekakucity Records seems to be his song. And in the Marie no Kakuu Sekai manga included in the first-print booklet of the same album, he does something unthinkable...
Interestingly enough, Kokonose Haruka's hair is also black.