Jang Keun-suk
Jang Keun-suk and Park Shin-hye were both cast first, with director Hong Sung-chang stating that the two were well-suited to convey the "fresh" idol stars concept he wanted. Lee Hong-gi (a singer with the idol group F.T. Island) had been a child actor, and this was his acting comeback after a five-year break (his last acting project being "Kkangsoon" in 2005). Jung Yong-hwa made his acting debut with this role, which he auditioned for whilst preparing to debut with his band CNBLUE in Japan.