I feel like a lot of people would benefit from rereading chapter 1 (and the whole beginning while they're at it). Sunbae has not treated Hanjoo well from the jump.
I think it's still far too early to make a call on whether Hyung is truly better seeing as we don't know his true motives and if he's had anything to do with why people seem to avoid, dislike, or not even notice Hanjoo. The fact that people treated him poorly as a child before he ever got lost in the mountains and met Hyung gives me some slight hope. But so far, Hyung has treated Hanjoo kindly and gently and he really deserves that.
I just really dislike the way Sunbae has treated Hanjoo throughout. He's very dismissive and pushes to get the responses he wants. It's plainly obviously Hanjoo is often uncomfortable yet Sunbae doesn't care. The interest he's shown lately was only sparked by Hyung showing up and that's six months too late.
Not the Lump Spark shirt!!