Song Jae-ho

as Professor Choi

as King

as Sang-beom

as President Hwang (16 episodes)

as Yoon Du-ho

as Dae Tong-ryeong

as Mr. Yoon

as Yoo Tae-jin (18 episodes)

as President

as Kwak Han-soo

as President Lee (16 episodes)

as Jang Goon-bong

as Jung Byung Do (20 episodes)

as Vice-Principal Kim Young Ho (62 episodes)

as Oh Joong-ho

as Choi's Uncle

as Min Chi-sung

as No-seung

as Ji-ho's father

as Priest Kim

as Cha Hyeon-min (17 episodes)

as Kang Oh-Joon (16 episodes)

as Sun-ho's father

as Suh Nak-Chun (130 episodes)