there are currently four Juon films out there. Juon 1 and 2 were originally made for Japanese TV (or was it direct to video?). They were fairly cheap looking but apparently very scary, which resulted in the director finding funding to remake them for theatrical release (ie Juon-The Grudge and Juon2). Now with The Grudge having proved something of a minor worldwide success the same director is remaking it AGAIN this time with US cash, set in Tokyo and starring Sarah Michelle Gellar.
The TV films are available on DVD in Japan but have no english subtitles. Juon-The Grudge is the one I have seen and is now available from a few outlets.