He's an internist at Jahan Hospital. He is a cranky doctor who takes the lead in going on voluntary medical service abroad. He may be a rogue, but he's the finest doctor. People call him an arrogant, rude and unruly "mad dog," but he doesn't mind it at all because thank to this nickname, no other doctor would try to get on his nerves. Surprisingly, he is the most caring brother and uncle to his older sister and his niece, and he's as generous as a saint to his patients. His late father was in the forefront of overseas medical services. Back then, he resented his father for being neglectful of his family while he was busy taking care of his patients. But when he followed his father's footsteps and served in Africa, at last he came to understand his father. But as a side effect, he decided not to get married. Dating is fine, but forget marriage. He doesn't want to hurt his family like his father did. He would commit to practicing medicine for his entire life. After serving in Africa for several years, he returns to Korea when his brother-in-law, who is the director of Jahan Hospital, calls for help.