The series follows characters Bong Sang-pil and Ha Jae-yi who form the Lawless Law Firm.

Sang-pil, a former gangster turned lawyer, seeks to avenge his mother and fight against those with absolute power.

[4] Ha Jae-yi is a lawyer of high integrity who works with Sang-pil after she is suspended for assaulting a judge.

The series was a commercial hit and became one of the highest-rated Korean dramas in cable television history.

[5] 18 years prior to the events of the series, Cha Moon-sook murders a man critical of her late father.

Lawyer Cho Jin-ae discovers the truth of the event due to pictures taken by Noh Hyung-joo.

Hyung-joo is forced to leave her husband and young daughter, Ha Jae-yi, behind to flee the country.

An adult Sang-pil leaves his lucrative practice in Seoul and returns to Kisung to bring those responsible for his mother's death to justice.

Jae-yi, who has been suspended from practicing law after assaulting a judge, loses her job, and also returns home to Kisung.

They and their associates oppose the Lawless Law Firm both inside and outside the courtroom by using underhanded tactics, including murdering Dae-woong and framing Sang-pil for it, bribing or threatening witnesses and assaulting Jae-yi.

Despite the obstacles in their way, Sang-pil and Jae-yi succeed in revealing Moon-sook's crimes in court and successfully plead their case against her.

Jae-yi and Sang-pil then return to Seoul to help Prosecutor Cheon Seung-beom fight against corrupt officials.

A former gangster turned lawyer who takes advantage of loopholes in the law and boasts an excellent win rate.

Prior to becoming a lawyer, he spent time in prison for his gang activities and has lived a life of hardship.

A lawyer of integrity who ends up being temporarily disbarred after verbally attacking a corrupt judge in court.

[7] Raised by her father after the disappearance of her mother, she returns to Kisung jobless and in disgrace, but chances upon Sang-pil, who offers her an opportunity to regain her license.

[10] She has ordered murders, rigged trials, run a corrupt charity for her own gain, and chosen city leaders favorable to her cause.

Due to the costs of her law degree, he owes loan sharks a good amount of money.

Due to her evidence of Moon-sook's crimes, Oh-joo ordered Woo Hyung-man to kill her, but the latter spared her life instead.

Police officer and formerly the lead detective in charge of the Choi Jin-ae and Noh Hyung-joo cases back in the day.

He later meets their now-adult children and agrees to help them piece together the evidence in order to bring Cha Moon-sook's crimes to light.

In early 2018, Namoo Actors revealed that Lee Joon-gi was in talks to play a lawyer in an upcoming drama.

[15] The first script reading took place on February 28, 2018 at Studio Dragon in Sangam-dong, Seoul, South Korea.

[16] The results of the script reading reportedly helped Studio Dragon to build confidence in the drama.

[17] For her portrayal of an honest lawyer, Seo Yea-ji was named as an honorary police officer.