I have about 10 movies i love from japan but i am gonna mention only a couple
Moon Child - Hyde and Gackt star and Hyde is a vampire, its a good movie even if you dont like gang movies it will make you laugh and cry and ogle Gackt's great butt
Suicide Club - Do not watch if you have hemophobia because you might have to be taken to the mental institution (just in case hemophobia is the fear of blood) very bloody and entertaining tho...
Audition - If you want the best scare of your life watch this movie, well actually the last half hour more or less but to get it all watch this, very bloody and scary!
one movie i do wanna see tho is Battle Royale 1 and 2!