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."

Dumped by her boyfriend of 15 years for gaining weight, a lawyer gets help from a hotshot personal trainer to get in shape and turn her life around.