It's a live-action Hong Kong adaptation of the notorious 1987 anime. That in turn was based on the first of a series of novels, but no, this is based on the anime. I like it, but it's so dissimilar to the original that it's hardly worth comparing them.

To refresh your memories, the anime was a riot of Lovecraftian demon sex and violence. Its premise was that for hundreds of years, mankind has been negotiating and maintaining peace treaties with the inhabitants of the extradimensional Black World. There are demon ambassadors. There's a Black Guard, who police the boundary without ever letting ordinary people know that the supernatural exists. This isn't just a monster-bash. On the contrary, it's creating a very specific backstory on which its story will depend. However the live-action film jettisons almost all of that. I wouldn't even say that it's the same genre as its anime predecessor. Instead it's simply a Hong Kong action film with demons in it, rather than freaky boundary-pushing SF horror noir.

1. We still have a hero called Renzaburo Taki (Leon Lai) who does the same demon-policing job as before and even starts the film by having a similar encounter with a demonic prostitute, but the key difference is that this time he's not a loser. This movie isn't horror. Its Taki can be expected to take down any demon he's up against, with only the usual setbacks facing any action hero.

2. Demons are just demons. They don't have official status or ambassadors. Instead the powerful ones will simply have made themselves rich and will be running lots of companies.

3. This invalidates pretty much the entire plot of the anime. Instead we simply have cops and demons struggling with their natures and trying to decide what to do. Furthermore Taki's partner Makie has been split into two characters: his male partner (Jacky Cheung) and his demon ex-girlfriend (Michelle Reis). Jacky Cheung is a tough cop, just like Lai, but he's also half-demon on his mother's side and trying to hide this from their superiors. You might be wondering why he took this job in the first place. Keep wondering. As for Reis, she's staggeringly beautiful and he dumped her three years ago because he was worrying about getting too close to her. He doesn't want to turn out like Jacky Cheung's parents, which shows what can happen when a man falls in love with a demon. Demons are the enemy, aren't they?

This probably sounds as if I'm about to dismiss the live-action remake, but until the messy last act I thought it was really good. The crucial thing is that they've got fresh themes to replace the ones they're removing. No one's ever heard of demons trying to negotiate with humans before. Thus this isn't a war between established factions, but instead something much more personal. Everyone's got to decide for themselves what they think is right and if their conclusions bring them down on the side of the good guys, they'll have the entire world against them. This is solid stuff. I loved it. Tatsuya Nakadai's son Roy Cheung thinks he's nuts and would like to overthrow him and take over his financial empire. Lai's boss treats all demons as the enemy. Jacky Cheung has some heavy personal issues under all the high-kicking and gun-toting.

Unfortunately Act Three is a bit flabby. The film becomes a mish-mash of fights, tragic decisions and slightly silly rubber costumes. It's not horrible, but anime is better at this kind of thing.

Does the film work? Hell, yes. It's being directed with more punch and dynamism than you'd have got from the equivalent live-action film in Japan, or indeed America, Britain, France or anywhere else. This is what Hong Kong does best. Sequences will be shot like fight scenes whether or not they happen to contain fighting. It's exciting to watch, but they do that without sacrificing the genuinely good story they've got going. This film isn't just bubblegum. Admittedly I'm less keen on the structure of the third act, but then again it's going for tragedy in a way you won't find in the anime. That makes up for a lot. The ending in particular is excellent.

I had no problem with the actors, although I don't have much to say about most of them because I'm not as familiar with Hong Kong cinema. Michelle Reis is certainly easy on the eyes, though. One name that did surprise me though was Tatsuya Nakadai, who's been making a splash in Japanese cinema since the 1950s and was Akira Kurosawa's favourite leading man after that falling-out with Toshiro Mifune. He's one of Japan's few internationally recognised stars. I never knew he spoke Chinese.

What about the sleaze? The anime version had breasts coming out of its ears, so to speak. The live-action version has decided not to go there, but you can't say they're not making an effort. Reis spends a lot of time discreetly naked, for instance, after demonic transformations or disgusting tentacled things. Personally I got the impression that the film was trying to feel sleazy while in fact being almost family-friendly, which might sound daft but they actually do rather well at it. I think they capture something important in the original's tone. I also like the special effects, which make good use both of CGI and practical rubber costumes. Regardless of the change in genre, this feels like Wicked City. I respect that.

Would I recommend this? Yes. It's good. I'm sure there are a thousand Hong Kong films like this, but that doesn't diminish the skill and flair that's gone into this one. It has tragedy, emotion and strong themes, often voiced by Nakadai. I loved the scene where he's in the hands of the police and talking about how he'd thought mankind was better than this, or alternatively his observations that men are afraid of their emotions and trying to hide them. The third act's a little shapeless, yes, but not so much as to derail the film.

Compared with the anime, though, it's tame. "Normal" is the word I'm looking for, I think. A fan of the anime watching the Hong Kong film will probably think it's a whitebread version, but still be impressed anyway unless they're just looking for sex and violence. A fan of the Hong Kong film watching the anime will decide that Japan is full of freaks.