Main •
Park Eun-bin as Lee Jung-joo/Choi Jung-joo, a hot-tempered judge who is incapable of holding her emotions to vent shameless defendants with unspeakable words. She presides at the Seoul District Court. •
Yeon Woo-jin as Sa Eui-hyeon, a righteous independent judge who is excellent in his use of law and ethics to reach judgement. He is assigned to the same division as Lee Jung-joo. •
Dong Ha as Do Han-joon, a prosecutor who graduated with Sa Eui-hyeon at the top of his class. •
Na Hae-ryung as Jin Se-ra, an intelligent third generation
chaebol who is a law school student and a former idol singer.
Supporting People at Korea University Law School • as Ha Young-hoon, a former prison guard and law school student who is responsible for creating the misjudgment research team. •
Jung Yoo-min as Hwang Min-ah, a former Blue House bodyguard and current law school student. • Hong Seung-beom as Nam Yoon-il •
Jung Yeon-joo as Lee Seon-hwa, a single mother who is a member of the misjudgment researching team.
People at court •
Lee Moon-sik as Oh Ji-rak, a chief prosecuting attorney. •
Lee Chang-wook as Jeong Chae-sung •
Woo Hyun as Choi Go-soo •
Bae Hae-sun as Moon Yoo-seon • as Song Ho-chan • as Seo Dae-su • as Oh Mi-ja • as Kim Moo-sik • as Lee Cha-won •
Oh Na-ra as Judge Yoon
Extended •
Kim Hae-sook as Yoo Myung-hee, a professor in law school. She inspired Lee Jung-joo to become a judge. •
Lee Deok-hwa as Do Jin-myung •
Choi Jung-woo as Sa Jeong-do •
Park Ji-a as Jang Soon-bok •
Seo Cho-won as Supporting •
Ji Seung-hyun as Choi Kyung-ho, Lee Jung-joo's older brother •
Kim Hee-jung as Eom Sin-sook, Lee Jung-joo's mother and a janitor at the courthouse. ==Production==