IRIS (2009)

Xianjun (played by Lee Byung-hun) and Siyu (played by Jung Jun-ho) are senior officials at the NSS (National Security Service), both of whom fall in love with their beautiful boss, Shengxi (played by Kim Tae-hee), but the latter is mutually attracted to Xianjun. The deputy director, Baishan, assigns them to rescue a scientist, who before dying entrusts a USB drive to Xianjun. Baishan secretly sends Xianjun to assassinate North Korea's number two figure; Xianjun accomplishes the mission but is killed to silence him. Out of brotherly love, Siyu lets Xianjun go. Just as Xianjun prepares to flee with Shengxi, he encounters an explosion. Xianjun escapes to Japan and reconciles with the North Korean agent, Shanhua (played by Kim So-yeon), who is tracking him, and they work together to survive. Shengxi, who narrowly escapes death, firmly believes Xianjun is alive and conducts numerous illegal investigations. Xianjun is hunted in Japan, leading to the tragic deaths of his savior's family. Desperate, Xianjun turns to North Korea and, alongside a terrorist organization, attacks the NSS headquarters, where he finally meets Shengxi, but they still cannot recognize each other. Xianjun finally uncovers the secret of the USB drive, finding out that Baishan is the murderer of his father, and there is a mysterious organization behind it called IRIS. High-level talks between South and North Korea are underway, while the chief of security plots to create a terrorist explosion. During the investigation, Shengxi is captured by terrorists, only to find her lover now appears as an enemy, welcoming them to a more brutal conspiracy...