- James Tang
- Â Choe 4 episodes, 2024
- Ren Hanami
- Â Madam Guan 4 episodes, 2024
- Eugene Ko
- Â Yeon Moyong 4 episodes, 2024
- Andrew Lee
- Â Paul 4 episodes, 2024
- Kwon Hyuk
- Â Paul's subordinate 4 episodes, 2024
- Jo Yoon-soo
- Â Chae Jagyeong 4 episodes, 2024
- Choi Jung-woo
- Â Professor No 4 episodes, 2024
- John D. Michaels
- Â Dr. Jonas Hilm 2 episodes, 2024
- Joe Nowell
- Â US Agent 2 2 episodes, 2024
- Shin Yeon-Woo
- Â Chae Jagyeong (young) 1 episode, 2024
- Enrico Dennis
- Â Russian 1 episode, 2024
- Kim Seon-ho
- Â Choe unknown episodes
- Cha Seung-won
- Â Lim Sang unknown episodes
- Kim Kang-woo
- Â Paul unknown episodes
