Yeon Woo-jin

Young Han Jeong-hyeon/Lee Suk-kyu

Captain Jo Min-gook

"Jang Yoon"/Jang Do-hoon

Oh Soo-min

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.

Lee Yeok, Grand Prince Jinseong/Nak-chun, later King Jungjong Baek Su-ho as young Lee Yeok Choi Jung-hoo as child Lee Yeok

Eun Hwan-ki, the cold and timid CEO of Brain public relations firm. He avoids people as much as possible by hiding out in his penthouse office or covering himself in a black hoodie. Park Ha-joon (ko) as young Eun Hwan-ki

Lawyer Gong Gi-tae (ep. 7)

So Jung-woo

Gong Gi-tae

Lee Han-kyung, Lee Hee-kyung's eldest brother

Lee Jae-hee

Joo-wal

Han Jae-kwang Cho Yoon-woo as young Jae-kwang

Hwang Tae-pil

Bang Woo-jin

Dong-soo