Shinya Tsukamoto's films have always focused on the family unit, or more precisely on the unity between couples. Most of the attention for his work has concentrated understandably but somewhat disproportionately on the sci-fi / cyberpunk elements, the theme of bodily mutation, and the similarities with the works of Davids Cronenberg and Lynch. Although these are certainly major factors, at heart Tsukamoto's films consistently deal with relationships and the influences that threaten them.

Rarely was this more apparent than in A Snake of June, which recycles the love triangle premise of his earlier films Gemini and Tokyo Fist, but dispenses with the horror/fantasy overtones of the former and the bloodspurting brutality of the latter. This is the story of a couple first and foremost, not a genre film that happens to have a couple as its subject.

The couple in question are Rinko (stage actress Asuka Kurosawa) and Shigehiko (novelist Yuji Kotari), whose physical mismatch (she a lithe beauty, he an overweight, balding, obsessive-compulsive neurotic) is reflected in the complete lack of intimacy between them. They connect as human beings, but they live more like friends than as lovers and lead nearly independent lives. Both seem comfortable with this coexistence, but the desires that lurk beneath its surface are brought out with the introduction of a third element into the equation. When Rinko receives a package of candid photographs of herself masturbating and the sender (played by Tsukamoto himself) contacts her with the threat of exposing them to her husband, she submits herself to the anonymous voyeur's sexual games. If she wishes to get hold of all the negatives and prints, Rinko is to comply with a set of assignments that place her constantly on the borderline between humiliation and pleasure - the voyeur knows exactly what Rinko's personal erotic fantasies are and makes her act them out one by one.

Although such material lends itself all too easily to an exploitative approach, Tsukamoto keeps his attention rigorously focused on the characters and their emotional responses. A Snake of June never once feels like exploitation - or worse, pornography - and the only explicitness on offer here is in the actors' faces rather than other parts of their anatomy. The film is a character piece, one that despite its intimate point of view manages to incorporate the characters' position in society. In order to confront her with what she's allowing herself to hide, the blackmailer forces her to play out her innermost desires in public. He coerces her into breaking a barrier, to behave in a way that requires her to violate society's rules of how she's expected to behave. Because it's those rules that have allowed her to continue living in denial of her own desires, to co-exist instead of sharing her life with her husband.

It's in this aspect that the film reveals hidden depths in its attitude towards the female protagonist. Although the premise would suggest a very male perspective, with the woman taking the role of object of sexual gratification, the real gratification and liberation are Rinko's. Like the female protagonist of Tokyo Fist, she develops into a self-aware and self-confident individual in touch with her own personality, a woman who doesn't let the rules imposed on her by her environment decide how she should live her life. Without going so far as to call A Snake of June feminist, Tsukamoto's film displays a degree of empathy with its female protagonist that unfortunately is still all too rare in the male-dominated world of cinema (it won the Special Jury Prize in Venice, where the feminist French director Catherine Breillat was one of its staunchest supporters).

Despite doing away with the genre-based surface that has been the most eye-catching element of the director's previous work, stylistically this is instantly recognisable as a Tsukamoto film. Shot in blue-tinted monochrome, the images are as beautiful and the photography and editing as intense as any of his earlier efforts. Although he places more emphasis than ever on the human form as is - untainted by mutation or mutilation - the director does occasionally add some of his beloved biomechanical imagery. Though seemingly at odds with the realistic tone of the film, these moments this time round have a more symbolic function, serving as the visualisation of the characters' emotions. These fantasy scenes, only two in number, are both experienced by Shigehiko, whose obsession allows for such delusions: his discovery of a huge glob of filth in the sink (an exaggerated, almost mutant version of what most of us hesitantly scrape from the drain on occasion) is what forms the catalyst for these nightmarish visions.

With its focus on human beings and organic life (also present in the incessant downpour that forms the backdrop to Rinko's sexual reawakening - see our interview with the director for more on the function of rain in the film), rather than machinery and physical deformations, A Snake of June might well be the thematic culmination of all of Tsukamoto's past work. For the same reason it might also prove to be the most accessible point of entry for the uninitiated, illustrating that an artist doesn't necessarily have to compromise his message in order to communicate with a larger audience.