There was this pretty short manhwa of an unrequited love where one decides to take a long trip away on like, Jeju, to get over his childhood friend or something, and right in the day before the trip ML arrives at his house drunk and asks if he can follow him to Jeju
I can't remember the name but it's finished, does anybody now?
Kang Jun is a kid cursed with being too smart, at an age where he has little morality to use that intelligence in a better way. He's using his brains to stay on top and not be a victim in a fucked up system, so I can't blame him for being two-faced, it's quite literally a matter of survival.
All the while exactly his age makes him arrogant, too sure of himself and surprisingly impulsive with his feelings.