Don't enter the tent if you're expecting a steamy lesbian brief encounter. Japanese sensibility, thank the gods, is much more refined than something so crud. Besides in the liberated 21st C there is so much dial a porn why travel back to the 60's to criticise what never could have been.
What unfolds here is the depiction of need, fantasy, wish fulfillment and the use of allure to entice weakness and then to smash those lives upon the sharpened stakes of feminine guile.
The bored middle class housewife finds fantasy and reality in her art class friend, her saviour and her mortal danger. Her muse senses the need and draws her into her web. Initially entailing the victim to make small sacrifices until they become larger and larger to prove her love. Ending with the demand to enter oblivion at the behest of the siren.
Meanwhile her family is torn apart by the demands. The friend simply measures her beauty with the fawning and supplication of her vassals need.
It is slow placed, shot using various focal settings, capturing the essence of the claustrophobic worlds of need, desire and the avenging angel.
The naked bodies, scandalous in the 60's, now in an age of image bombardment, have a diminished potency. The beauty of the protagonist still projects as does her guile. It is difficult to gauge whether people are more psychologically aware than 4 decades ago. Judging by the comments on the film, I guess not. This is where the power of the film resides as an allegory of power, the femme fatale, the emotional vampire who sucks the vitality out of the needy. They know they are being used but in the grand scheme of the emotional panorama at least this is one form of acknowledgement, better to be used, than invisible to all.