A very, very, very good read. Beautiful plot, fascinating art.
However, I'm not satisfied at all with the ending. Mashiro isn't the Kuro Rui loved, neither is Rui the Rui Mashiro loved. So it didn't make sense to me that they loved the real them and not just chasing the illusion they loved and seeking it in the other party.
"I'm not Kuro, I'm Mashiro"
Monokuro Limit