The filmmaker had previously made a movie about peasants scraping by on an island, and that Marxist valourisation of the underclass may carry over into this film. That is what the DVD introduction suggests, anyway. The war is endless – samurai lead hordes of commoners to their deaths – and two women who are left behind have to rely on murder and looting corpses in order to survive. Onibaba (demon-hag) is a spirit in Japanese folklore, but I'm not sure if it's just this political background that draws the demons out.
The film opens on a shot of a hole in the ground surrounded by the tall swaying grass. This continues to be a repeating visual motif. Scenes are separated by shots of the grass rustling in the wind in slow motion, almost sensually swaying in the sun. At the beginning of the film, intertitles come up informing us that this hole in the grass has been here since the dawn of time. Hachi, in seducing his dead friend's widow, tells her that men and women have been copulating for thousands of years, and that her mother-in-law's talk of sin is a fabrication. In one scene, Hachi, mad with lust, is running in the field and stumbles across the hole. Not the kind he was looking for, but he still goes ahead and inserts his voice into it, receiving a pleasing echo. A crude symbol, but the film is not above using them. The widow is shown carrying an empty bucket of water when Hachi starts flirting with her. Hachi at his horniest grabs a blade and starts stabbing the air and grass outside.
And the mother-in-law, the demon-hag, intrudes on these bubbling desires. She needs the marriage contract to remain in place so that the young widow remains bound to her. So she warns her against Hatchi, then tries to seduce him instead. Finally, she turns to superstition – frightening her daughter-in-law back into her cage. She acquires the demon-mask from 'the most handsome man in Kyoto'. She confesses to him that she has never seen anything beautiful: her sexuality is twisted into resentment and murderous anger at the powers that be.
She is despicable: callous and manipulative. But when she wails that underneath the mask and her disfigurement she is human after all, we can't help but sympathise. If she is a demon, it is because she is desperate, fending for herself amidst an eternal brutal war and betrayed by the capricious wantoness of the young. Those twin pressures swallow her up. The hole amidst the grass ends up being her grave.