You probably need more than just a passing awareness of Japanese cinema to have even heard of pinku eiga, or pink film, a uniquely Japanese form of softcore pornography that flourished in the 1960s and 70s. Initially the product of low budget independent companies, their widespread success ensured that the bigger studios eventually got in on the action – Nikkatsu in particular produced so many that their name became almost synonymous with the genre. The form remained popular until the mid eighties, when it lost a lot of ground to home video, which enabled fans to enjoy the content in the privacy of their own homes.

Unlike their Western equivalents, if the West can be said to have one, pink films were almost always more than just a string of sex scenes loosely linked by ludicrously under-developed plots or shabby comedy. Narrative and character were given the same degree of attention as the erotica, and even social or political aspects were incorporated into many stories. The genre's heyday may be over but the films are still being made, though it's rare to find one getting any sort of distribution outside of Japan. Enter Redemption Films and their DVD release of Bitter Sweet [Bitâ suîto], a recent entry into the genre whose dramatic focus is the increasing instability and non-permanence of modern relationships. It's the second film – and second pink film – from director Mitsuru Meiki, whose 2003 debut feature was the slightly more widely seen Hatsujô kateikyôshi: sensei no aijiru [The Glamorous Life of Sachiko Hanai].

Shoko and Tamura are a young couple soon to be married, but Shoko is starting to have her doubts, something she reveals over a restaurant meal to her close friend Mika, who is single but eagerly on the lookout for the right man. Late the following evening, Shoko returns to the restaurant to talk to owner and chef Kudo (played by writer-director and some time actor Hitoshi Ishikawa). The two remember each other from the registry office a couple of days earlier – when Shoko was collecting her certificate of marriage registration, Kudo was requesting the document to file for divorce. Shoko has approached him to discuss her doubts, a woman on the brink of marriage seeking the advice of a man whose own has begun to fail. She ends up seducing him and an uncertain relationship begins – Shoko quickly falls in lust with Kudo, but he is reluctant to emotionally commit to her, his weariness with his home life not yet strong enough for him to put pen to divorce papers.

It's a melancholic view of the changing face of relationships and marriage in a country that once pointed to its low divorce rate as a key element of its social stability. Sure, the requisite number of sex scenes are there and are typically shy of showing either genitalia or pubic hair (both forbidden under current Japanese censorship laws), but they nonetheless benefit from an unglamorous, matter-of-fact eroticism and an almost seamless integration with the main narrative. It's never just about arousing the audience – the sexually forward females and initially surprised and even alarmed males are sign of changed times in a once rigidly patriarchal society, and each such sequence plays out in a way that both expands on character detail and advances the story. When Kudo has sex with his wife, for example, the act is frantic but devoid of passion, its conclusion an almost mechanical Kleenex wipe-off. There's no emotional investment on Kudo's part, something he admits to and cares little about in the argument that immediately follows – the true state of their marriage and feelings for each other are all captured in this short but telling scene.

For a film of just an hour in length (a popular running time for pink cinema), Bitter Sweet's deceptively unhurried narrative is surprisingly busy with incident and detail. The key supporting character of unhappy, heavy-drinking Yoshida, for example, is initially unidentified, a broken man haunted by his memories. But when he shows up unexpectedly at the restaurant and drunkenly assaults Kudo, it becomes clear that the two are not only connected but have a troubled history, and one that is destined to affect Kudo's own future. Even the background characters of Tamura and Mika have their moment when the former is seduced by the latter, an encounter that tells you a surprising amount about the feelings and attitudes of both. Such detail is only possible because the performances, in complete contrast to most western equivalents, are as convincingly natural and understated as they would be for any straight-up drama.

If you're looking for an introduction to modern pink cinema then you could do a lot worse than Bitter Sweet. The nudity and (for the most part brief) sex scenes are made to feel as integral to the story as the dialogue, while the drama and social subtext is just well enough developed to find the film an audience beyond the genre fandom.

Not the most vibrant of transfers, the non-anamorphic 1.78:1 picture is nonetheless intermittently better than I was expecting, given that it's sourced from an analogue tape master (the giveaway tracking blips are at the very bottom of the screen when viewed without overscan). Contrast is good and detail level reasonable, at least on well lit close-ups – on wider shots the picture softness is more evident. Zooming in to fill the widescreen TV frame markedly depreciates the picture quality.

A functional Dolby 2.0 mono soundtrack whose unfussy mix and sound recording reflect the film's obvious low budget. By the halfway mark, however, a quite pronounced synchronisation issue has developed that stays for a while, but does sort itself out before the end.

Japanese Box – Short Film Showcase (11:27)
A short film by UK director Tobias Tobbell that has nothing to do with the main feature except for its Oriental characters and the word 'Japanese' in the title. A horror story of sorts involving two girls, a mysterious box and an overdressed private investigator, it's driven along by the sort of emotionless, dual character voice-over you only seem to find on British short films and is not even a little bit creepy. The late film integration of anime-style drawn imagery momentary enlivens things. The picture has a fuzzy YouTube quality and almost no shadow detail.

There is also a brief Stills Gallery, a Gallery of frame grabs from the above film (why?), Trailers for other Redemption titles Belcebu, 99 Women and Venus in Furs and an extracts from 16 albums on the Triple Silence label. I know this is a sell, but there's actually some interesting stuff in this last one.

An interesting and quite involving example of modern-day pink cinema whose pleasingly low key approach to both its drama and its sex scenes gives it an air of realism rare for sex dramas or any nation. Redemption's DVD is not all it could be, losing points for its non-anamorphic picture and a few more for the analogue tape source, but it's sometimes better than those two handicaps might make it sound. The synchronisation issue is another thing entirely, although if you're watching the subtitles and, well, the other action, you may not even notice.