A Bittersweet Life

Sun-woo, a high-ranking enforcer loyal to Kang, is tasked with shadowing Hee-soo as part of the boss's vigilance. He follows her through the city and ultimately accompanies her to a music recital, keeping a careful, unseen watch. The quiet surveillance hints at Sun-woo’s own loneliness and foreshadows a growing, uneasy fascination with Hee-soo.

Sun-woo discovers Hee-soo is having an affair with another man when he confronts them at Hee-soo's home. He beats the man in a controlled, brutal display and contemplates turning Kang in for his discovery. He ultimately spares the couple on the condition they end the relationship, a decision that seeds Hee-soo’s lasting enmity toward him.

A Baek family associate arrives demanding Sun-woo apologize for beating Baek's men. Sun-woo refuses, defending his actions and his loyalty to Kang. The confrontation deepens the sense that Sun-woo's standing is already precarious and that trouble is closing in.

Agitated by the fallout, Sun-woo is kidnapped by Baek's henchmen and subjected to torture. Kang intervenes with a phone call, signaling that Sun-woo's betrayal is known and demanding he be given a chance to redeem himself. The tension tightens as Sun-woo endures the interrogation, weighing his options.

Sun-woo forces a perilous escape from the torture and vows revenge on Kang and Baek for the betrayal. He resolves to take matters into his own hands, choosing action over silence despite the personal costs. The vow marks a turning point toward a violent personal vendetta.

Sun-woo delivers a farewell gift to Hee-soo and tries to purchase a handgun for his retaliation. The arms deal goes wrong, and he ends up killing the arms dealers in self-defense. This act pulls him deeper into a web of violence and retribution.

The arms dealer’s brother vows vengeance and arranges a confrontation at an ice rink. Sun-woo lures Baek there and kills him, yet sustains a serious injury in the process. The killing escalates the conflict and seals Baek’s fate within Sun-woo’s vendetta.

Driven by rage and loyalty betrayed, Sun-woo battles his way into Kang's nightclub. He confronts Kang directly, unleashing years of grievance about loyalty and punishment without justification. The confrontation ends with Sun-woo killing Kang.

Baek's henchmen, trailing Sun-woo, collide with Kang's men in a brutal gunfight inside the nightclub. Sun-woo is wounded as the two mob factions clash around him, turning the venue into a war zone. The violence marks the final collapse of Sun-woo's former world.

Outnumbered and bleeding, Sun-woo makes his final stand, but the arms dealer's brother closes in. He delivers a fatal shot, ending Sun-woo's violent blaze of vengeance. The death underscores the merciless logic of the criminal underworld.

Bleeding out, Sun-woo recalls watching Hee-soo's music recital—the one moment when he truly smiled. The memory anchors him in humanity just as darkness closes in. It is a quiet, haunting counterpoint to the violence surrounding him.

The film returns to an earlier, quiet image of Sun-woo looking out over the city below. After ensuring he is alone, he begins shadowboxing his reflection in the glass, a rare, contented smile spreading across his face. The scene lingers on a man who found a momentary happiness only in violence.