- Seo In-guk (Lee Hyun)
- Jang Na-ra (Cha Ji-an)
- Park Bo-gum (Jung Sun-ho/Lee Min)
- Lee Chun-hee (Kang Eun-hyuk)
- Choi Won-young (Lee Joon-ho/Lee Joon-yeong)
- Im Ji-eun (Hyun Ji-soo)
- Min Sung-wook (Son Myung-woo)
- Kim Jae-young (Min Seung-Joo)
- Jun Kwang-ryul (Lee Joong-Min)
- Son Seung-won (Choi Eun-Bok)
Hello Monster — S1E6
Episode: The Blood of a Murderer
Air Date: 2015-07-07
Runtime: 61 min
Overview
Lee Hyun meets with Prosecutor Shin Jang-Ho concerning Park Young-Chul's case. Jang-Ho informs Lee Hyun has experienced two cases of memory loss in relationship to his parents' deaths. Also, that Lee Joon-Yeong never leaves any bodies to be found for his murder cases. In order to investigate the Park Jeung-Woo murder case, Lee Hyun is coerced to join Team 1 as an official advisor. Lee Hyun hires Jung-Sun-ho to be Lee Jung-Ha’s attorney because he believes he is innocent.