Guest Stars Kim Joo Hun as Lee Sang In Jang Gyu Ri as Sun Byul Jang Young Nam as Park Haeng Ja Park Jin Joo as Yoo Seung Jae Kang Ki Doong as Jo Jae Soo Lee Eol as Go Dae Hwan Kim Soo In as Go Moon Young (Child) Moon Woo Jin as Moon Kang Tae (Child) Lee Kyu Sung as Moon Sang Tae (Young) Choi Hee Jin as Kang Tae & Sang Tae's Mother Jung Ji Hyun as Publishing House Staff Ko Han Min as Publishing House Staff Chun So Ra as Publishing House Staff Jo Yi Hyun as Dinosaur Boy Jung Seung Gil as Book Critic Kim Jae Chul as Book Signing Parent Lee Ji Hae as Book Signing Parent
