Monster Boy Online

Kim Yoon-seok - Seok Tae, Yeo Jin-gu - Hwayi, Cho Jin-woong - Ki Tae (as Jin-woong Jo) , Hyun-Sung Jang - Jin Seong (as Hyeong-seong Jang) , Seong-gyoon Kim - Dong Beom, Park Hae-Joon - Beom Soo (as Hae-jun Park) , Nam Ji-Hyun - Yoo Kyung (as Ji-hyeon Nam) , Ji-Eun Lim - Yeong Joo, Yoo Yeon-Seok - Park Ji Won, Seong-kun Mun - CEO Jin, Kyeong-Yeong Lee - Im Hyung Taek, Cheol-woo Han - Detective Kim, Joo-wan Han - President Jeon's Attendant, Jang In-sub - Detective Chang Ho, Yoon-seok Jeong - Hwayi (child) (as Yoon-Seok Jung)