Set against the sprawling, neon-lit backdrop of Seoul, *City Hunter* follows Lee Yoon-sung, a brilliant MIT-graduate intelligence operative working at the Blue House. Secretly, Yoon-sung’s entire existence is engineered for vengeance. Raised in the Golden Triangle by his
surrogate father, Lee Jin-pyo, a ruthless survivor of a tragic 1983 military betrayal, Yoon-sung discovers that he was trained solely to assassinate the "Council of Five"—the corrupt South Korean politicians responsible for the massacre of his biological father and twenty-one comrades. Jin-pyo ruthlessly molds Yoon-sung into a lethal weapon, driven by an unyielding thirst for retribution.Upon returning to South Korea, Yoon-sung adopts the vigilante persona of the "City Hunter," executing elaborate schemes to expose the high-ranking officials. However, his mission is immediately complicated when he meets Kim Na-na, a resilient bodyguard at the presidential residence who works tirelessly to pay off her father's hospital debts. Despite his initial cold exterior, Yoon-sung falls deeply in love with Na-na, forcing him to balance his blood-soaked quest for vengeance with protecting the woman he cherishes. Adding to the tension is Prosecutor Kim Young-joo, an incorruptible lawman obsessed with capturing the elusive City Hunter, unaware that the vigilante is operating just steps away from him.As the narrative deepens, Yoon-sung’s worldview is challenged. He refuses to resort to murder, instead exposing the corrupt officials to public disgrace and legal ruin. This creates bitter friction with Jin-pyo, who views mercy as a fatal weakness. The stakes reach a boiling point when Yoon-sung uncovers a shocking family secret: Prosecutor Young-joo is actually his half-brother, and the true mastermind behind the 1983 tragedy includes someone even closer to the Blue House than previously imagined.Betrayals mount, loved ones are held hostage, and the body count rises as Jin-pyo goes rogue to slaughter the targets himself. In a tragic climax, Jin-pyo attempts to execute the President—who is Na-na’s surrogate father and Yoon-sung’s biological father—at the memorial site. To save the President and halt the
cycle of violence, Jin-pyo takes the blame, sacrificing his life and securing Yoon-sung's freedom. Ultimately, the corrupt officials face justice, and a wounded Yoon-sung reunites with Na-na, finally stepping out of the shadows to claim a peaceful future.