Titlle : 세상 어디에도 없는 차칸남자 / Innocent Man Also Known as : The Nice Guy Never Seen Before / No Such Thing As Nice Guys / Chakkan Namja Previously Known as : 차칸남자 / Nice Guy Genre : Melodrama , Romance Episodes : 20 Broadcast period : KBS2 Cast Soong Joong Ki as Kang Ma Roo Kang Chan Hee as Kang Ma Roo ( young ) Moon Chae Woon as Seo Eun Gi Park Si Yeon as Han Jae Hee Park So Young as Han Jae Hee (young ) People around Ma Roo Lee Kwang Soo as Park Jae Gil ( Best friend ) Lee Yoo Bil as Kang Choco ( Ma Roo's half sister ) Jo Sung Ha as Sung Min Hyuk ( Professor University ) People around Eun Gi Kim Young Chul as Seo Jung Gyu ( Eun Gi's Father ) Lee Sang Yeop as Park Joon Ha ( Eun Gi's Lawyer ) Jin Kyung as Hyun Jung Hwa ( Eun Gi's Secretary ) Kim Seo Ra as Eun Gi's mother People around Jae Hee Kim Tae Hoon as Ahn Min Young Woo Young as Secretary Jo Jo Hwi Joon as Seo Eun Suk ( Eun Gi's half brother )