Throw Away Your Books and Rally on the Street (1971)
"Probably the pick of the bunch. Good soundtrack, from memory"
Pastoral: To Die in the Country (1974)
"Another film by Terayama. I preferred Throw Away Your Books, but this one is still worth a look."
Funeral Parade of Roses (1969)
"A gay inversion of Oedipus Rex, as performed by Japanese transsexuals. Said to be an influence on Kubrick’s A Clockwork Orange."
"Imagine a shampoo commercial crossed with a horror film. It is easily one of the strangest films I have ever seen"
"Note: Don’t watch the trailer – it doesn’t do the film justice and would spoil the surprises."
"Pitched somewhere between performance art and narrative feature, I enjoyed the film but it’s probably not to most people’s taste."
Black Tight Killers (1966)
"Campy fun with a well-judged tone."
"Not really ‘trippy’, but the sets and cinematography are extraordinary. An indisputable work of art." http://www.imdb.com/title/tt0058279/?ref_=nv_sr_1
Available on DVD.
And one non-Japanese suggestion from Andrew:
Jerzy Skolimowski's Deep End from I970 (starring Jane Asher, and featuring a cameo by Diana Dors)
When I commented that "I’m sucker for all that sixties stuff. split screens, trip scenes etc....
Still haven’t grown out of being wowed by The Knack (And How To Get it)..."
Andrew pointed out that Deep End "isn’t trippy. It’s more grimy and dour, in an England’s-best-years-are-behind-it kind of way.
"I don´t like colour movies and I can hardly think about colour. It really cheapens things for me and there´s never been a colour movie I've freaked out over except one, this thing called Deep End, which had really great art direction." - - David Lynch, 1982
Here's the whole thing but with Italian subtitles....