A Story Written with Water (1965)

A mother and son have a strong, almost sexual, bond through moments present and past. The father of the past (who has died of Tuberculosis, revealed shockingly), the mother's current liaison, and the son's wife all re-enforce roles of sexual inadequacy with the two main characters (Mother, Shizuko, and son, Shizuo). Time is blended together, and the film ends up being an incredibly interesting melodrama with much of the (Japanese new wave staple) political put on backburner. A subplot involving the son's lack of sexual interest in his wife, and his mother's lack of sexual fulfillment in her lover (husband to be, I'm not sure) adds to the development of the incest tone.