Jeon Jin-seo

as Arthur

as Jeon Jae-ha

as Lee Jun-yeong

as Young Cha Yul-mu

as Self

as Lee Yoon-hee's Younger Brother

as Teenage Eugene Choi

as Child Heo Joon-jae/Kim Dam-ryeong

as Kang Hyun-Min (child)

as Prince Youngchang

as Yoon Tae-Woon (young)

as Han Sa-oh

as Kim Cho-Rok