Dead Friend
better known as The Ghost, is a 2004 South Korean horror film. It is one of a number of recent South Korean horror films set in a girls high school; the trend began with 1998's Whispering Corridors. It stars Kim Ha-neul as Min Ji-won, Nam Sang-mi as Su-in, Bin (Jeon Hye-bin) as Eun-seo, and Shin Yi as Shin Mi-kyung. Ryeong directly translates into "The Ghost". Both Kim Ha-neul and Nam Sang-mi previously starred together in Too Beautiful to Lie.
Plot
Three friends from the same high school are conducting a séance with a bunshinsaba - a traditional South Korean ouija board. As the spirits are called by Eun-jung (Lee Yun-ji), the planchette of the bunshinsaba starts jumping up and down: At the same time, her sister Eun-seo, who was sleeping in the next room, wakes up screaming. When Eun-seo comes out, she has an argument with Eun-jung about conducting the séance rather than studying. After she leaves, Eun-jung says she wishes the ghost had taken her sister away and then jumping to join her friends in bed jokingly tells them that if they don't send the ghost back it will kill them. They are all unaware of the planchette moving around the board on its own. Nor are they aware of Eun-seo being attacked by a ghostly water-based presence in the kitchen.
After a visit to her doctor, an amnesiac Min Ji-won (Kim Ha-neul) finds out that now her brain waves have stabilised, there's a good chance she may get her memory back. She's decided to leave college, leave her mother and go overseas, to make a new start for herself.
In time-honoured movie tradition, though, little snippets of her memory start to come back in her dreams - and they're almost always tainted by some frightening figure she can't place. Not only that, but they seem to be continually connected to water, whether in the dream itself or by the medium of a knocked-over glass of drinking water next to the bed. But soon enough, inexplicable things begin to happen to her in reality as well - echoes of her dreams, the ghosts of her forgotten past invading her waking life.
Just at this time, Ji-won gets a blast from the past: Yu-jung, an old friend from High School, comes to find her after she saw her in a dream - and not only that, one of the other girls, Eun-seo, has died after telling this girl she had seen something bizarre. It's not long before Yu-jung also has a terrifying supernatural experience with the ghost Eun-jung never sent back.
Now three of her closest friends from High School are dying under mysterious circumstances. But what is the identity of this ghost, how is it linked to her own forgotten past, and can Ji-won find out how to save herself?
As Ji-won tried to find out the mystery and went on the falls. She remembered what exactly happened to Her Friends, including herself. She founds out that she's the one who pushed Su-in in the water but her friends pushed her too. And both of them started to drown but Su-in tried to save her. They found Su-in's dead body.
As Ji-won went home to see her mother, everyone turned into a twist. Her mother was possessed by Ji-won and the Ji-won was actually Su-in. Su-in entered Ji-won's body . Then Her mother or Ji-won splashed water. And the ghosts started to upraised and wanted to get Ji-won's body which possessed by Su-in's soul. But Su-in grabbed the broken piece of a vase and cut her wrist but was saved in time by her friend and sent to hospital. The Original bad Jiwon didn't get back to her original body and instead possess Su-in's mother.