Oh man, unless I'm off my mark, that's a movie I've been hearing about for years. It was released in Japan a few years ago and is apparently extremely hard to get a copy of. What little I know: a person recieves a VHS tape of someone doing something extraordinarily creepy, perhaps near that person's bed with the person asleep in it.

I'm remembering little about it, apart from that it's supposed to be incredibly suspenseful.

it's listed on imdb. no references to what's on the video tape, but if you watch it, you end up dead.