The ML yearns for the MC, and in his presence, behaves accordingly - he's sociable and polite. However, he's actually indifferent towards, and I'd say annoyed by anyone who isn't his hyung.
The ML is mostly indifferent to others and has a rather serious, unapproachable exterior, but he isn't indifferent to the MC at all. He has his mind set to finding the MC and getting to know him, and no one can stop him.
The ML has a disdain for pretty much anyone who isn't the MC. He's very closed off, harsh and abrasive. To an extent, this is first directed at the MC as well, but changes later on.
MC is an emotionally closed off man wearing a pokerface at best and a serious frown for most of the time, who is also involved in criminal activities. However, he has a very soft spot for his crybaby ML.
The ML has a horrible, violent, dog shit personality, and the MC experiences it at first as well. However, through certain events, this changes abruptly and the ML is obsessed with the MC and pretty much has only eyes for him.
The ML is an introvert who tends to be snarky and rather distant from people, he'd rather stay home or avoid crowds and meetings with people altogether. He doesn't have any friends either. However, he falls for the MC during their rivalry for the MC's high school best friend. He even beats up a piece of shit who tries to blackmail him and put the MC's career future in danger! He also breaks down and cries because he can't get over his feelings for the MC!!
For You Who Grieves