Responses
Either your idea or he is her child with someone else, since they are so similar.
(=・ω・=)
As far as I got the raws Mano is a human, but the soul of Carbel's first love is inside him. Which is why his condition is a bit special, but he is no angel or something like that.
I did think that he was somehow related to Carbel's dead girlfriend. I just guessed angel because of the pictures of him with angel wings plus his white hair and skin.
Wait, so there is no way that Mano is a human, right? Wait, is he an angel? Like, maybe the soul of Carbel's late girlfriend reincarnated? Well, I don't know, but he's definitely not a human.