Lies, deceit and fake smiles. This is what Kurogane sees when he looks towards Fai with eyes full of suspicion.
In the dead of night, when Fai whimpers into his pillow, Kurogane's eyes soften into confusion while staring into the darkness in the direction where Fai should be.
The moment Fai grabs a hold of Sakura's arm, just before she falls, Kurogane can see the slight crack in the façade. The worry - sincere and raw - spilling through. His eyes admire with a somewhat weird sense of pride.
His eyes also show sadness when Fai's view hardens: an eye rough and jagged with confused hatred rather than false smiles.
It's only when Kurogane and Fai's eyes shut in content that all seems right in the world.
... sugar...
