Main •
Lee Jong-suk as Ahn Joo-hyung : A senior associate at Kyungmin Law Firm on the 7th Floor. Despite having nine years of experience with the firm he has no desire to eventually start his own practice. He chose to become a lawyer because he enjoyed the logical problem solving. •
Moon Ga-young as Kang Hee-ji : A newly hired lawyer at Johwa Law Firm on the 8th Floor. She has an optimistic personality and sympathises deeply with her clients. With two years of experience, she is the most recent addition to the meal crew after her predecessor resigns. •
Kang You-seok as Jo Chang-won : An associate from Junggong Law Firm on the 5th Floor. His skills are often overlooked as he is from a wealthy family. He shares a close friendship with Sang-ki. •
Ryu Hye-young as Bae Moon-jung : A senior associate who works at the same law firm as Joo-hyung. She has a kind but competitive personality, and is dedicated to her work as a lawyer. •
Im Seong-jae as Ha Sang-ki •
Kim Do-hoon as (Ep. 1) : • Ko Geon-han as Park Kyung-hyun (Ep. 1) : Joo-hyung's client. A legally blind man accused in an assault case. •
Yoon Kyun-sang as Kim Ji-seok : Moon-jung's husband and high school friend of Joo-hyung. He works as a nurse in a university hospital. •
Nam Yoon-ho as Cha Jung-ho (Ep. 3–4) : Joo-hyung's client in a divorce case. Husband of Park Soo-jin. •
Lee Yoo-young as Park Soo-jin (Ep. 3–4) : Joo-hyung's ex-girlfriend. •
Kim Tae-hoon as Hee-ji's father (Ep. 4) • Jeon Jin-seo as Moon Chan-young (Ep. 9–10) == Production ==