When Jo Hyun Jae was working on his character he didn’t think that Han Do Jun is the type that changes dramatically. He also thought that Han Do Jun wasn’t like that as a child but the environment he grew up in made him the way he is as an adult. Han Do Jun was raised under a father that made incompetent decisions and he had to survive somehow in a family that was always chasing after power and recognition. Han Do Jun had no choice but to change when he was living as an outcast and even more so since he even took care of Han Yeo Jin that betrayed him later. Jo Hyun Jae explained that in order for Han Do Jun to survive in that environment he had to have ambition.
Jo Hyun Jae carefully went over the character Han Do Jun so due to this there was a lot of preparation involved in the process. For example – facial expressions, the eyes, voice, and even breathing methods – he researched and studied all these. He read the script until he was fully satisfied. He thought that it was very important for him to be into Han Do Jun’s character so he researched and kept on studying the character again and again.