Many people suggested this movie to me when I mentioned it. I experienced the film using the Korean audio track with English subtitles. Oh Dae-su (played by Chi Min-sik) seems to enjoy flirting—though whether he's a womanizer isn’t explicitly stated—and has a wife and a young child who is now two years old at the start of the story. He’s in a prison waiting room after offending a woman he was flirting with, and a friend eventually secures his release. However, while he’s calling his wife to tell her he'll be home, he's abducted. Confined to a small space with only a television for company, he receives food and care but is denied freedom. He tries to end his life on several occasions. To stay in shape, he follows workout routines from TV, and he begins digging an escape route using chopsticks. A news report reveals that he’s been falsely accused of murdering his wife. Fifteen years pass without any explanation, and then he's suddenly released. The remainder of the film details his efforts to discover why he was imprisoned, who was responsible, and what happened to his daughter. The movie is fast-paced, intense, and deeply emotional in numerous ways. It contains moments of violence, but Oh Dae-su’s determination to get revenge on those who put him away and locate his daughter propels the narrative forward. There are also psychological elements explored, and the film does reach a conclusion—it isn't one of those ambiguous stories that leaves you wondering about the perpetrator. If you watch it through to the end, you will receive all the answers. I suggest watching it, but don’t expect something easygoing or relaxing.

Source on TMDB