Responses
You said same age, maybe because of uniforms?
One of them can be freshman and other is senior, so uke is 2 years older than seme. Being an uni student and 20 yo makes sense with this,I think... ╮(￣▽￣)╭
I think that Kazushi is dead or in coma because there were a few hints like when his brother told him to go check the exhibition because it might be the last chance he has to see it. Also when he gets to the exhibiton and sees Rui crying, at that moment Rui lookka older but if you see the first pages they seem to have the same age. Also when he keeps hearing in the news about an unidentified boy who was encounter by the police in the snow.