Kim Sung-su

as Sim Seok-hun (12 episodes)

as Ik-seong

as Jeong-hwan

as Hwang In-Woo (40 episodes)

as Jung-Woo

as Ahn Do Young (20 episodes)

as Self (cameo)

as Kim Jung-wook (51 episodes)

as Major Park Dae-suh

as Self (1 episode)

as In-ho Lee (54 episodes)

as Self (2 episodes)

as Oh Seung-won

as Lee Soo-hwan (20 episodes)

as 김건우 (1 episode)

as Jon

as Yoon Suk-Ki / Alex Yoon (15 episodes)

as In-cheol

as Park Ki-tae (18 episodes)