Ryeong (2004)

Synopsis
South Korean director Kim Tae-gyun's horror picture Ryeong (AKA The Ghost) concerns Ji-won (Kim Ha-neul), an intelligent and comely young student who suffers from complete amnesia. A mysterious 'accident' befell her, wiping out long term memories of friends, acquaintances, and past events. Then, just as Ji-won begins to struggle with this mnemonic void, and looks ahead to rebuilding her life, her old friends begin dying odd, inexplicable deaths and ghostly, relentless visions plague her. Upon further investigation, Ji-won learns that she and three female friends once forged a tough, invincible quadrumvirate. As the body count surrounding Ji-won rises, and accusers blame her for the occurrences, she begins to delve more aggressively into her past, and disturbing memories come flooding back that explain the rising tide of supernatural vengeance against Ji-won and her friends. ~ Nathan Southern, All Movie Guide