"Aviva" portrays the relationship between Eden and Aviva, and how the conflicts and difficulties in balancing the masculine/feminine balance within themselves extends outward and challenges their connection. Both characters are played by both a man and a woman each, and the film is narrated for the most part by Eden's female side.
Eden and Aviva and their journey as a couple; from courtship to marriage, to divorce and finally into a deep friendship - it's theme is the masculine/feminine duality in each individual and how that balance or imbalance affects the relationship between them, so both characters are played by a man and woman.