Sympathy for Mr. Vengeance

Sympathy for Mr. Vengeance Hangul RRBoksuneun Naui Geot lit. Vengeance Is Mine or Revenge Is Mine is a 2002 South Korean film directed by Park Chanwook which follows the character Ryu trying to earn enough money for his sisters kidney transplant and the path of vengeance that follows. It is the first part of The Vengeance Trilogy and is followed by Oldboy 2003 and Sympathy for Lady Vengeance 2005.

To get money for the operation, Yeongmi Bae Doona, Ryus radical anarchist girlfriend, suggests kidnapping the daughter of an executive that fired Ryu. They kidnap Yusun Bobae Han, the daughter of Dongjin Song Kangho. The girl stays with Ryus sister, who believes Ryu is merely babysitting her. Ryu and Yeongmi successfully collects the ransom from Dongjin. However, his sister discovers the plan and commits suicide to stop being a burden to him. Ryu takes Yusun and his sisters body to a suburban riverbed they used to frequent as children, and begins to bury her. Distracted by the burial and unable to hear, Ryu is unaware when Yusun slips into the river, and she drowns.As Dongjin mourns his daughter, he hires an investigator to find her kidnappers. Dongjin finds Yeongmi and tortures her. Yeongmi apologizes for Yusuns death, but warns Dongjin that her friends a terrorist group will kill him if she died. Unfazed by the threats, Dongjin electrocutes her. Meanwhile, Ryu locates and murders the organ dealers. He returns to Yeongmis apartment and sees the police removing her corpse. ........

Source: Wikipedia