It's like watching two films at once. On the one hand, it's an Akira Kurosawa black-and-white classic that's addressing profound social dichotomies, so one feels that one should approach it with reverence and that the critics would presumably be wanking themselves into comas. This is understandable. After all, it's extremely classy and nearly two and a half hours long. However it's also a police procedural based on an Ed McBain 87th Precinct novel, so at the end of the day Kurosawa meant it to be a "catch the bad guy" movie like a million Hollywood schlockers before and since.

This even handicapped the film on its original Western release, incidentally. The critics talked it up as if it were an arthouse film rather than a thriller, so it got put on the arthouse circuit where it didn't belong. It flopped.

It thus seems right to begin by discussing High and Low as if it were any other thriller adaptation. For starters, I like Ed McBain. I think I've even read this particular book, King's Ransom, although there are so many 87th Precinct novels that I couldn't say for sure. Obviously the book's shallower and more throwaway than the film, but that doesn't mean the comparison is all one way. Carella, Meyer, Kling and co. are more lively and vivid than their counterparts here, while a further problem in badass cinema terms is the fact that the film strikes me as being slightly rarefied. It's too classy. No matter how unpleasant or sordid Kurosawa tries to make his kidnappers and junkies, it ends up feeling like social commentary rather than schlock. Fundamentally he's just not a hard-boiled guy, although in fairness the man's so talented that his attempts at imitating it are interesting anyway and at least he's getting nearer than you'd have got from his contemporaries like Ozu or Mizoguchi.

McBain on the other hand has always been delighted to fill his books with retards, perverts, full-blown drug wars and people getting hacked to bits with axes. He wrote 87th Precinct books for fifty years and even the early ones have an immediacy that means they never feel dated.

Kurosawa's movie is more literary than McBain's book, although of course McBain also wrote more literary novels under his other names, e.g. Evan Hunter. Kurosawa's movie though is special for its integrity and social awareness. You've got actors like Toshiro Mifune and Tatsuya Nakadai getting all the screen time they could want to fully communicate their characters' struggles, in a film with a scope so wide that the story ends up being bigger than any one person. Mifune is the first act's protagonist, but he drops out of the action once the police procedural's properly under way. You've got the lives of the rich being juxtaposed with those of the working classes, plus junkies and criminals. This would be clearer, albeit in a slightly misleading way, if you translated the Japanese title literally (Heaven and Hell).

The film starts with Mifune being approached by executives on the board at their shoe-making corporation, who want his help in taking control of the company. They plan to make cheap rubbish. Mifune boots them out angrily and soon reveals that he's taken extreme steps to protect his position, but then a bad phone call comes in and all the rules change.

Mifune's playing it tight here, despite his character's understandable fury at pretty much everything. He's not a nice man, but you can't doubt his integrity and even when he's offscreen, he's the backbone of the film. The police on the other hand are practically heroes. They're efficient, diplomatic and leaving no stone unturned in their search for the truth. Tatsuya Nakadai is tall, urbane and the perfect leader. Kenjiro Ishiyama is squat, mean and completely bald, which makes me wonder if he's not the counterpart of McBain's Meyer. Unsurprisingly all the actors are as good as you'd expect, but one last memorable performance is from Tsutomu Yamazaki, whom I last saw in Departures, Japan's 2008 Oscar-winner for Best Foreign Film. I love his face. It's squashed and angular, like a caricature of itself.

The turning point in the film is the lengthy but mundane scene of the police summarising their findings so far, which is deliberately a bit too long and going into enough detail that one's subconsciously prepared for the impending change in story emphasis. This second act feels quite different from Mifune's story, which was hard but passionate. It's occasionally funny, as with that railway guy and his train sounds, while on the other hand there's also a scary moment, but for the most part this is simply a detailed look at police work. It's impressive, thoughtful and never flagging under its running time, but there's a plot reason why it doesn't feel as urgent or dangerous as it might have done.

I liked it. However I liked it partly as a study of the breadth of Japanese society, from the wealthy apartments that look like sets from Goldfinger to the old guy surrounding by rubbish at his trash burner.

There are a few technical tricks. Most obvious is the pink smoke in a black-and-white film. More subtle these days would be the shots taken inside a car while we're driving along, which almost feel as if Kurosawa's set them up exactly like back projection and then wrong-footed you by shooting them for real. For some reason I noticed those.

Unsurprisingly this film has been remade a bunch of times. There are two Indian versions, Inkaar (1977) and Dongala Veta (1978). I'm starting to suspect that India really likes Kurosawa. Then there are a couple from 2007, one from Hong Kong (Bong ga) and the almost inevitable Japanese TV remake. And you thought Hollywood had caught remake fever recently. There had also already been an adaptation of King's Ransom as part of an American 87th Precinct TV series when Kurosawa's film came out, despite the fact that the book was only published in 1959.

You don't need me to tell you that this is an important film. There's a reason why Kurosawa's regarded as one of the world's all-time greatest directors. However it's not actually a particularly tense thriller, although I like the fact that it's far from certain that the police investigation isn't going to grind to a halt as their quarry gets clean away with it. The police are arguably just as important in their symbolic role as the great levellers of society, dealing without favour with all men and occasionally passing personal comment afterwards. "That house gets on your nerves. As if it's looking down at us." When it comes to crime, we're all the same.