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."

• Lee Min-ho
• Park Min-young
• Lee Jun-hyuk
• Kim Sang-joong
• Cheon Ho-jin
• Yang Jin-sung
• Shin Young-jin
• Kim Sang-ho