As our main character laments his obsession with love and death, he thinks he's the only one looking towards the high school boy, that his crush is one-sided. Somehow, he's missed the obvious fact that, whenever his eyes scan for the comforting sight of the boy, so do the boy's for his.
In the last frame, as the brightly lit train roars past the stunned boy, he sees the two men shooting for each other's embrace - intimate and warm. A mix of confusion and wonder painted his face, he stood witness to something beautiful and fleeting, almost intangible. It was a version of Kanou that he has never seen before, animated and expressive and bright - the same brightness that Kanou himself often uses to describe the boy with, only he, Kanou, is yet aware of this. He is not aware of his own good qualities, and always puts himself down. Understandable, considering the intolerant society that he lives in, but still a shame nonetheless.
I love this manga. A huge step up in maturity from the author's previous works.
Thank you for the chapter!