Jang Tae-Joon (Lee Jung-Jae) graduated from the Korean National Police University and worked as a detective. He wanted to gain more power and decided to work in the National Assembly. Now, he is the chief aide to a 4-time lawmaker. He has excellent intuition, a cold-blooded decisiveness and a strong desire to win. He was able to place his lawmaker in the position of the party representative, but Jang Tae-Joon has higher ambitions.
Meanwhile Kang Sun-Young (Shin Min-A) is a first year lawmaker who got elected through proportional representation and is a spokesperson for her party. She worked as a lawyer and hosted a current affairs TV program prior to becoming a lawmaker. She is ambitious and does her job well. Kang Sun-Young has an awkward relationship with Jang Tae-Joon, whose boss is a rival of the senior lawmaker who got her to become proportional representation lawmaker.