Season 1 of Chief of Staff premiered on June 14, 2019.

Jang Tae Joon 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 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.

Season 2 of Chief of Staff premiered on November 11, 2019.

The real political players behind the spotlight take a dangerous gamble. Super Adviser Jang Tae Joon heads towards the peak of power and fiercely struggles for survival.

Jang Tae Joon worked as the chief aide to Lawmaker Lawmaker Song Hee Sub. He now returns as a lawmaker and achieves the height of his power.