Chicago Typewriter- The male lead wasn't the nicest to the female lead at first, but once he warmed up to her, which actually happened very quickly, he was always there for her and always thought about how his actions would affect her before doing them. I can't say that he never did anything wrong or that he was flawless as a person, but he tried to stay true to his morals to the very end by trying not to do anything bad. Even when he did make mistakes, he regretted it and tried to make up for it. You also can't help but like his character as it is very lovable and memorable. The only thing Chicago Typewriter has that doesn't match your request is that this drama does have a love triangle but, the second male lead never initiated anything with the main female lead, so frankly it's a very inconsequential love triangle.
