as Gyeong-hwan (adult)
as Jin-su
as Han Min-oh(14 eps)
as Kim Jun-young
as Baek Joon-ki(15 eps)
as Self(2 eps)
as Self(1 ep)
as Kim Jun-young
as Jin Young-Min(16 eps)
as Jung Tae-yang(50 eps)
as Self(1 ep)
as Seok Jun-su(20 eps)
as Teacher Park
as Dong-gun
as Self(1 ep)
as Seo Ki-hyun(16 eps)
as Lee Ho-sung(19 eps)
as Lee Hyun-myung(10 eps)
as Noh Jung Do
as Kyung Woo-jin
as Jae-wook
as Self(1 ep)
as Bojang of Goguryeo(20 eps)
as Self(1 ep)
as Jung-hoon
as Yoon-chul / Charlie
as Cha Jin-oh(16 eps)
as Self(1 ep)
as Go Suk-Bin(50 eps)
as Noh Jung-Do(1 ep)
as Il-yeong
as Kim Gangu(22 eps)
as Joong-suk
as Teenager TaeSoo
as Yoo Sung-geun
as Kim Han-soo
as Employee
as Jjaeng
as Han Ji-hoon(30 eps)
as Lee Chang-seob
as Self(10 eps)
as Self(6 eps)