Oldboy (2003)

After being kidnapped and imprisoned for 15 years, Oh Dae-Su is released, only to find that he must find his captor in 5 days.

Storyline
An average man is kidnapped and imprisoned in a shabby cell for 15 years without explanation. He then is released, equipped with money, a cellphone and expensive clothes. As he strives to explain his imprisonment and get his revenge, Oh Dae-Su soon finds out that his kidnapper has a greater plan for him and is set onto a path of pain and suffering in an attempt to uncover the motive of his mysterious tormentor.