y'know what, I'm starting to think about it in a more general or broader perspective. Mincheol used to be so different, a sweet guy who loves his girl, but still he turns into this trash. This is just proof that anyone can become ... anyone. In this case, Mincheol seems to be affected mostly by his colleges and bosses in his workplace, and he always seems so eager to prove himself because he always feels inferior, lesser person in society. Now idk if the story is trying to say that, but it could very well be in my opinion.