Kim Min-gi

In Hoe

Park Do-jun

Prince Bogum

Yi Do, Prince Chungnyeong. Gu Hyun as 5-year-old Yi Do Joo An as 1-year-old Yi Do Kim Ro-woon as baby Yi Do

Jeong In-sol: Classmate of Hae-kang, Yoon-dam and Woo-chan. He is the class president and gets excellent grades, but yearns to play badminton with his new friends.

Choi Kang-joon

Lim Ju-young Park Ju-hwan as young Ju-young (ep. 1)