Officer Black Belt

Lee Jung-do is introduced as a skilled black belt in multiple martial arts disciplines, including taekwondo, kendo, and judo. Balancing his passion for video games with his job as a delivery rider at his father's fried chicken restaurant, he leads a seemingly mundane life.

After completing a delivery, Jung-do witnesses an incident involving a dangerous parolee. He steps in to assist probation officer Cho Min-jo in subduing the individual, showcasing his martial arts skills and bravery.

Impressed by Jung-do's actions, Kim Seon-min, the head of the probation department, convinces Jung-do to join their team as a martial arts officer. This new role allows him to apply his skills to handle aggressive probation violators and marks the beginning of his career in probation enforcement.

Seon-min quickly becomes a mentor and close friend to Jung-do, who begins to view him as an older brother figure. This relationship profoundly influences Jung-do's sense of justice and dedication to his new role.

Jung-do's first significant assignment is monitoring notorious child abuser Kang Ki-jung, who has recently been released on parole. Alongside Seon-min and Min-jo, Jung-do is tasked with preventing Ki-jung from repeating his heinous crimes.

Despite their surveillance, Ki-jung reconnects with his accomplice Han Byung-soon and meets Kim Min-wook, a dark web pornographer. The trio conspires to create child exploitation content, escalating the severity of their actions.

As the situation escalates, Ki-jung and his accomplices kidnap a young girl. This critical event raises the stakes for Jung-do and his team, intensifying their urgency to intervene and stop the criminals.

Seon-min, Min-jo, and Jung-do are lured into separate locations due to a deceptive distraction. This leads to a deadly ambush orchestrated by former parolees seeking revenge, resulting in tragic consequences for the team.

During the ambush, Min-jo loses his life, leaving Jung-do and Seon-min devastated. Seon-min is severely injured and taken to the hospital, forcing Jung-do to confront the reality of their dangerous mission.

Despite his injuries, Jung-do realizes that Ki-jung and Byung-soon are hiding in a basement. He bravely confronts them, leading to a tense situation where he manages to rescue the kidnapped girl.

With Seon-min recuperating, Jung-do enlists the help of his friends to track down Ki-jung and Byung-soon. They work together to gather intelligence and resources to outmaneuver the criminals.

The group successfully locates Kim Min-wook, who provides critical information about a debit card he had given to Ki-jung. This information becomes a pivotal clue in tracking down the child abuser and his accomplice.

Using the lead from Min-wook, Jung-do and his friends corner Ki-jung and Byung-soon at a restaurant. This confrontation leads to an intense battle where Jung-do showcases his martial arts prowess.

In the fierce showdown, Jung-do defeats Byung-soon and engages in a final confrontation with Ki-jung. His determination and skill lead to a hard-fought victory, ensuring justice for the victims.

With the criminals apprehended, Jung-do and Seon-min return to their roles as probation officers. They are now more dedicated than ever to upholding justice and preventing future crimes.