So Ji-sub

as Manager Kim (10 episodes)

as Nam Gi-jun (7 episodes)

as Cha Moo-hyeok (6 episodes)

as Self (1 episode)

as Moon Do-seok

as Self (1 episode)

as Yoo Min-ho

as Moon Do-seok

as Han Yi-han (16 episodes)

as Kim Bon (32 episodes)

as Self (1 episode)

as Self (10 episodes)

as Woo-jin

as Choi Chil-sung

as Kim Young-ho / John Kim (16 episodes)

as Adult King Jeongjo

as Cafe shop owner (1 episode)

as Kim Ji Ho (10 episodes)

as Self

as Joo Jоong-won / "Master" (17 episodes)

as Hyeong-do (Ji Hyeong-do)

as Kim Woo-hyun / Park Gi-young (20 episodes)

as Cheol-min

as Lee Jang-woo (20 episodes)

as Ghost