Uhh maybe I haven't had enough coffee and don't understand the question right... But here goes... The Ju-on movies were the original Japanese version, written and directed by Takashi Shimizu. The success he ended up having as a result of both Ju-on movies, got him the attention of larger studios, one of which offered to allow him to do a brand new English version of The Grudge.
If you have already seen the American Grudge versions, you're gonna watch the Ju-on ones and you will get that "i've seen this before" feeling. Some of The Grudge (US) is *slightly* different but not by much, it very very close to some of the original Japanese.
As I usually feel, the Japanese versions were better lol. Might be my dislike of Sarah Michelle Gellar... Still though, this along with the Ring, I think the original language versions were better.