Guest Stars Seo Yi Ra as Sgt. Oh Soo Hyun Yoon Sa Bong as Unit Chief Jeong Yeon Joo Yoon Na Moo as Park Joon Seo Lee Kang Wook as Jung Yoon Ho Kim Min Ju as Oh Yoon Jin (High School) Park Jung Pyo as Insp. Yoo Kyung Hwan Cho Han Gyeol as Jang Jae Kyung (High School) Lee Sang Jun as Kim Woo Sung Seo Sang Won as Police Chief Bae Byung Ho Jang Hyuk Jin as Hwang Hong Suk
