Every day is extraordinary for five doctors and their patients inside a hospital, where birth, death and everything in between coexist.

The story takes place in Seoul, 2011. Lee Yoon-sung is a talented MIT-graduate who's working on the international communications team at the Blue House. He encounters dangerous situations while solving a variety of cases, both big and small, for people who need his help, and eventually becomes a "city hunter."

Kim Sun-woo is an enforcer and manager for a hotel owned by a cold, calculative crime boss, Kang who assigns Sun-woo to a simple errand while he is away on a business trip; to shadow his young mistress, Hee-soo, for fear that she may be cheating on him with a younger man with the mandate that he must kill them both if he discovers their affair.