It's an Edo-era show about assassins. They call themselves shikakenin (which means "instigator") or even artisans, while claiming only to murder those who harm people and society. I don't believe it. Even in this film, not everyone lives up to the shikakenins' professed ethical standards, although they'll kill clients who lie to them.

Killing people for money is presented here as an everyday business transaction. Our anti-heroes are:

1. DR BAIAN (played by Jiro Tamiya), an acupuncturist. His weapon of choice is needles and he might kill you on a crowded street, then revert to being a medical man and pretend to administer first aid. (DIDN'T ANYONE NOTICE?!?) He's handsome, likeable and always visits a prostitute before an assassination. (He dislikes killing women, but that's true of everyone in the agency and he'll still do it anyway.)

2. TWO RONIN FOR HIRE, including one played by Koji Takahashi who's super-cool and a loving family man, with standards. He'll get offered a lucrative proper job by a cop. How dirty must a cop get to be regarded as beyond the pale by a professional assassin? Well, here you'll find out.

There's a brothel madam, nudity and prostitutes. Well, a bit. Those aren't the focus, but instead more like "hey, this is a 1973 film about the criminal underworld, so what did you expect?" One prostitute says something so crude that my English subtitles ignored it.

This film is based on a novel by Shoutaro Ikenami and must have been a hit, because it spawned a franchise. There are two more movies in this "Hissatsu Shikakenin" series (although I could only find one of them), plus a long-running TV series with Ken Watanabe.

It's satisfying, dirty 1970s grittiness. Its protagonists couldn't be called heroic, but they have their principles and they're trying to do good. After a fashion, in their eyes. I didn't hate watching them do their jobs in this bloody, backstabbing world where life's cheap and no one's trustworthy. We meet scumbags who deserve killing. Also, pleasingly, the assassins might get beaten up by their targets and thrown in the river to drown. I'll be watching the second film in this series tomorrow.

The funniest thing here, though, is the underreaction to a possible incest-and-worse revelation.