To me, it looks like C-kun has feelings for B-senpai, considering he's the only one who has a face in the art. LOL But it makes sense, when C-kun thought "My body can't tell the difference between the two". That's when it hit me. C-kun only has his eyes on B-senpai (No wonder we can only see his face). Now that B-senpai called them 'Homo', C-kun was crushed. And A-senpai came to the rescue and punched B-senpai. That's when C-kun realized that they're really different. And C-kun started being aware of A-senpai, that we get to see him clearly (likewise with C-kun)
A Senpai