City Hunter

In 1893, 21 South Korean soldiers were deployed in a secret mission to eliminate some North Korean officers. Yet, halfway through the mission, the South Korean government decided against it and had the soldiers eliminated. Lee Jyn-Pyo was left as the sole survivor and swore to get revenge for his fallen comrades. To do so, he raised and trained the son of one of the soldiers that died who was also his best friend. 28 years later, that boy now a man, Lee Yun-Seon, arrives in Seoul to infiltrate the government and find out the identity of the 5 politicians that gave the elimination order. Yet matters start to complicate themselves when, despite Lee Jym-Pyo's orders to remain detached from people around him, Yun-Seon starts caring for Kim Na-Na, one of the Security Agents for the government.