A Japanese woman called Yoko is a volunteer worker for the elderly. She visits one of her newest people, an old American woman with a laziness disorder, and as she goes upstairs to clean she sees something shut a door, yet she's alone with the American woman.
She goes into the room to look, sees nothing, then hears a clicking / groaning from above her, but that's the attic. She goes up to investigate and sees nothing. She turns around to leave when the thing pounces on her. We see kicking legs, hear screaming, then legs get dragged up.
Next day when Yoko hasn't turned up for work, Karen, an American who moved to Tokyo with her boyfriend, is sent in as a replacement. She isn't attacked but lets loose a little boy (Toshio), from a cupboard.
What follows is a whirlwind of deaths of people who go into the house, including the "bed scene." A lady is followed home (the two spirits can leave the house) and this woman hides under the bed-clothes like a five-year-old, and rather shockingly, the boy spirit is under her bed cover, and drags her to her doom.
The chief of police, investigating Yoko's disappearance, tells Karen how he was on a murder case three years ago, murder of Toshio and the spirit woman. They were murdered, and a curse was born. As long as the house stood, death had stained it, it bore a grudge on all who entered, they were doomed to die.
The police chief later goes to the house to burn it down, but Toshio drowns him, leaving two cans of gasoline. Karen's boyfriend goes to the house to look for Karen. Karen goes there to look for him, and as she tries to burn down the house, see ending...