Unlikeable and abusive MC, somehow similar to sungah considering every help he gets has to fall from heaven (the main cast that won't ever give up on MC), and he won't hesitate in abandoning his friends because of his "low self-esteem". Hamin is a good reason to give this manga a try though, she was written to be an unconditional support to Joonwoo even if he lashes at her or do stupid things on his own without ever trying to talk with anyone, even if it's directly related to them. Her 'understanding' of him is practically omniscient, her trust and support are unconditional. Heck, you'd think the events with Lila would make him mature a bit just to get disappointed once again.
I don't think this is a harem, yuri, taeyang and sungah are just friends (not romantically interested in Joonwoo), Lila may try something but more like "you tried and failed, but thanks, I still owe you for trying", and, at least it feels like that to me, Hamin is the only one that grew from "who is that guy" to "interested" to "like". She deserves better, but the MC needs her so author will just make Hamin love that scum more every passing chapter.