Lee Joon-gi
After his mother was brutally murdered in front of him by the Thai Qing Faction's gangster Mao, Lee Soo-hyun (Lee Joon-gi) was adopted into NIS agent Kang Jung-ho's family. Together with Min-ki (Jung Kyung-ho), Jung-ho's son, Soo-hyun becomes an NIS agent. Soo-hyun met Ji-woo (Nam Sang-mi) when they were about twelve years old and has another fateful encounter with her 10 years later. Together they have promises for the future.