Karashimi no Beradonna, Japan 1973 (Belladonna of Sadness). It's an erotic animation that's apparently been restored into 4K quality and is now touring the world's movie festivals, which is where I saw it, too. Very aesthetic and beautiful artworkwise. As for the message, well, very pro-woman and critical of religious and sexual double standards. If I'd have to write it a slogan, I'd go for "The Devil -- standing by women, sexuality and birth control since Medieval France."
Also a bit ironic how it's an erotic animation with this theme, but I guess Japan was as restrictive of depictions of female genitalia back then as it is now, so there are only ever the faintest hints of outer labial lips, but mostly just blank crotches, yet instead a ton of visual euphemisms for the vagina, and a healthy representation of penises.
Either way, it was a very interesting thing to watch, and I guess I'm prime audience for the social message as well, so 9/10.