
no I don't think that's it. I don't hate him cause he is not rude, I don't like him cause he have zero development has a character in this plot. he never change or learn anything new and he burly talk to the MC until the MC told him his feelings all of sudden. he dosn't feel real, he just feel like stereotype someone force into the story. he just there.....nothing more then that.

lol from all the things you could've called him, a stereotype is the less accurate of them all. Nobody, including Jae Won, expected a small and shy guy like him to be able to defend himself, and yet we found out he is really good at martial arts and can fight against those scary guys at the begginning of the manhwa with ease. Nobody expected such a well behaved kid like him to drink and yet he was the first one to shug down the beer. Nobody expected a quiet guy like him to be so passionate about the things he loves, like his dog for example, and yet he is. Also, he does go through development and changes. At first, he doesn't know what he is feeling towards Jae Won, he really likes him and cares about him, but he doesn't know whether this is love or something else. He is also afraid of losing JW friendship so when JW confess to him, he panics and denies his feelings towards JW. Later on, however, when he is talking with his best friend, he realizes that he does love JW and decides from now on to do everything in his power to be together with him. So he builds up the courage to confess to JW and is honest and open about his feelings despite not being that good at expressing himself. He learns about himself and what he is feeling and tries to be honest, building up the courage to confess. That's development, that is change.

when I talk aboout Karam I think it's not really development to fail to get your own feelings. I don't think we talk about the same thing when I say development.
and no it isn't surpise to me 0_0 it still feel stereotype. his ability to drink dosn't make him a "badass" or better then the stereotype he is. I mean character trait's. again what passionate are you talking about? I never seen him getting emotions that much if at all in the WHOLE story. well only when he got piss off by the childhood friend. but that the only real emotion we ever sew. that was only ONE time ever!
the probalm that he dosn't really seem panic, we don't even see he panic in his thought's. so I won't call it "panic" he didn't panic. that's not how you act when you panic.
again what he learn about himself? I mean anything new? that he can love someone else other then himself? I fail to get what the change here. isn't kind of obvious?
the thing is he dosn't need courage cause the MC already confess. it's done XD so there is no change other then Karam just need to be honest like he could be from the start and say he feel the same way. in order to have change, you need a reason for it to happen. Karam never had any reason to reject him and he never show he had any conflict at all. YOU NEED TO SHOW THIS STUFF you know. but no instead we get some static guy that never change his face other then smiling.
again if the character is static, you need to give a reason why he become like this and why he need to stop been static. that never happen with Karam, he stay the same guy and will forever be a static character with zero development.

Well to be precise you havent seen him getting emotions because the chapter that show his isnt getting there yet. he's a slow type character so it's natural if the got the slowest development towards Jaewon compared to all.
and also, he's obviously need the courage to confess even if the MC is already like him because he's not like Junseo who already know that he's gay. Karam is new about this, and the reason why he rejects Jaewon first might be explained in the next chapters after this. Except you know how to read Korean, you cant say you understand it after just skimming the pictures, you know.
and last, he does change. he may be stay same as a guy who does smiling, but his smile towards Jaewon in the end of chap is different compared his usual. It gave a deeper impression like, there's a slight obsession or feeling of relief that we could catch on it. which he's not showing something like this to othersl. But he finally realizes that Jaewon is (finally) important to him. because it's 'Unripe expression' afteral.
I like Karam because he isn't the typical BL romantic interest. He isn't some alpha male who is constantly rude to the main character. He is shy, gentle and kind, but because he doesn't follow the mold of how a "seme" should behave, people here hate him.