Jang Hang-seon

as Nam Heung-Sik (124 episodes)

as Hak-soo's Father

as Deok-soo

as Monk Do-am

as Cheon Il-man

as Kang Kwan Jang (8 episodes)

as Park Chang-ha

as Office Manager

as Heukgae (24 episodes)

as Professor No

as Sim Pyeong-seop

as Mister

as Cheo-sun

as Yuk Chul-gu

as 이정민 (16 episodes)

as Jang Kil-bog

as President

as Woo Ji-Sup (17 episodes)

as Kong Jang-Geun

as Supervisor Kim (20 episodes)

as Jun-ho's Father (voice)