- Jung Woo-sung
- Â Lee Jung-Woo / ... 21 episodes, 2010-2011
- Soo Ae
- Â Yoon Hye-In / ... 21 episodes, 2010-2011
- Cha Seung-won
- Â Son-Hyeok / ... 21 episodes, 2010-2011
- Lee Ji-ah
- Â Han Jae-Hee 21 episodes, 2010-2011
- Kim Min-jong
- Â Kim Ki-Soo 21 episodes, 2010-2011
- Choi Siwon
- Â Kim Joon Ho / ... 21 episodes, 2010-2011
- Yoo Dong-geun
- Â Director Kwon Yong-kwan 21 episodes, 2010-2011
- Kim Young Ae
- Â Choi Jin-Hee 21 episodes, 2010-2011
- Lee Jung-Kil
- Â Jo Myeong-ho 17 episodes, 2010-2011
- Ryu Dam
- Â Amusement Park Shooting Gallery employee 17 episodes, 2010-2011
- Sean Dulake
- Â Andy 16 episodes, 2010-2011
- Lee Han-wi
- Â Park Sung-chul 16 episodes, 2010-2011
- Sung Hoon Chu
- Â Black Agent / ... 13 episodes, 2010-2011
- Jeong Ho-bin
- Â Deputy Director Kang Chul Hwan / ... 13 episodes, 2010-2011
- Kim Seung-woo
- Â Park Cheol-yeong 11 episodes, 2010-2011
- Jeon Gook-hwan
- Â Han Jung Pil 9 episodes, 2010-2011
- Park Yong-soo
- Â Hwang Ho-young 8 episodes, 2010-2011
- Ji-hoon Son
- Â Hong Jin Seok 7 episodes, 2011
- Yoshihiro Akiyama
- Â Black Agent 6 episodes, 2010-2011
- Park Chul-min
- Â Jang Ki Suk 6 episodes, 2010-2011
- Min-ji Lee
- Â Jessica 5 episodes, 2010-2011
- Hana Hwang
- Â Miss Cho 5 episodes, 2011
- Kim Jin-geun
- Â Park Seok Ho 4 episodes, 2010-2011
- Park Sung-woong
- Â Jin Young 4 episodes, 2011
- Chang-min Shim
- Â Choi Tae Hyun 4 episodes, 2011
- Cha Do-jin
- Â Athena Operative 4 episodes, 2011
- Bo Young Lee
- Â Jo Soo-Young 3 episodes, 2010
- Oh Chang-seok
- Â Lee Dong Hun 3 episodes, 2011
- Chan-Woo Jung
- Â Athena Agent Chul-Gyu 3 episodes, 2011
- Ricky Kim
- Â Viktor Sevcenkov 2 episodes, 2010
- Yong-gi Park
- Â Yoo Kang-Ho / ... 2 episodes, 2010
- Kim So-yeon
- Â Kim Seon-hwa 2 episodes, 2011
- BoA
- Â BoA 2 episodes, 2011
- Kong Jeong-hwan
- Â Seo Min-hyuk 2 episodes, 2011
- Lee Jae-yong
- Â Captain Kim Oh-gun 2 episodes, 2011
- Gun-Woo Choi
- Â Special Agent B2 2 episodes, 2011
- Heo Tae-hee
- Â BoA's Manager 2 episodes, 2011
- Ah-young Kim
- Â Special Agent B4 2 episodes, 2011
- Jin Goo
- Â Black Agent 1 episode, 2010
- Natallia Bulynia
- Â Waitress 1 episode, 2010
- Jeong Han-yong
- Â Jung Hyung-Joon 1 episode, 2010
- Byoungman Kim
- Â Amusement Park Shooting Gallery employee 1 episode, 2010
- Do Ye Sung
- Â Jung Kyung Won 1 episode, 2010
- Myeong Ji-yeon
- Â Hong Soo-Jin 1 episode, 2010
- Jeong Man-sik
- Â Athena Agent 1 episode, 2011
- Taemin
- Â Self 1 episode, 2011
- Onew
- Â Self 1 episode, 2011
- Yoo Tae-woong
- Â Seon Hwa's Husband 1 episode, 2011
- Choi Yong-min
- Â Nam Dong Shik 1 episode, 2011
- Max Chang Min
- Â Choi Tae Hyun 1 episode, 2011
- Ye-sun Lee
- Â Seon-hwa's Daughter 1 episode, 2011
- Kevin Brenneman
- Â DIS Agent shot in ambulance (uncredited) 1 episode, 2011
