A loose adaptation of the Japanese manga Old Boy by Garon Tsuchiya and Nobuaki Minegishi, the film follows Oh Dae-su, who is imprisoned for 15 years without knowing the identity of his captor or his captor's motives. When he is released, Dae-su finds himself trapped in a web of conspiracy and violence as he seeks revenge against his captor and falls in love with a young sushi chef, Mi-do.