Chae Sang-woo

as Ki Oh-seong (12 episodes)

as Teenage Joon-mo (12 episodes)

as Gook Young-soo (24 episodes)

as Young Sa-hyeon

as Eun Du Gyeol (20 episodes)

as Dan-jong

as Yeon Choong (young) (20 episodes)

as Lee Soon (young) (24 episodes)

as young Ha Ryu (24 episodes)

as Chunchu (young) (70 episodes)

as Lee Yoon Sung [Young] (1 episode)

as Min-woo