EMMA ALBERICI, PRESENTER: It strikes fear into the hearts of the Japanese, the petite pinkie finger or more accurately, the lack of it. In Japan the absence of this delicate digit usually means the amputee is the member of the country's notorious mafia known as the Yakuza. For gangsters hoping to go straight missing a pinkie often means missing out on a job with employers reluctant to take on former mafia members meaning many go back to a life of crime. But now one woman is helping these Yakuza by making prosthetic pinkies. North Asia correspondent Mark Willacy reports from Osaka.

MARK WILLACY, REPORTER: It's an impressive body of work and today prosthetics maker Yukako Fukushima is crafting a new pinkie for one of her clients, a former foot soldier in Japan's feared Yakuza.

YUKAKO FUKUSHIMA, PROSTHETICS MAKER (translation): In Japan having a missing pinkie means you are mafia. So if a man has no pinkie people will be terrified of him. That's why once they leave the Yakuza these gangsters struggle to get a proper job.

MARK WILLACY: In Japan there are an estimated 100,000 Yakuza and this mafia runs everything from protection racquets and prostitution rings to drug networks. These gangsters are easily identified by their all over body tattoos and often by their missing digits. Yubitsume or finger shortening has been practised in the Japanese underworld for hundreds of years. And is often a punishment meted out by a godfather for offences against the gang. Junichi Fujwara, not his real name, is a long time Yakuza enforcer, has decided to go straight. Because of gang secrecy and the fear of retribution we agreed not to show Mr Fujwara's face.

JUNICHI FUJWARA, FORMER YAKUZA (translation): I broke the gang's rules. I won't say what I did. So as a penalty my pinkie was cut off.

MARK WILLACY: Mr Fujwara has come to see prosthetics specialist Yukako Fukushima to have a refitting. He's recently put on weight and had a bit of sun so his specialist silicon pinky needs adjusting and re-shading.

JUNICHI FUJWARA (translation): When I quit the underworld I needed to get serious work. If my pinkie was missing I wouldn't even get an interview, let alone a job.

YUKAKO FUKUSHIMA (translation): In Yakuza circles word of mouth spreads very fast. I've even got clients who heard about me while they were in jail. So far I've made about 600 or 700 pinkies.

MARK WILLACY: The pinkie prosthetics business is booming, thanks largely to new tough laws aimed right at the heart of the Yakuza. This crackdown is flushing out more and more gangsters from the underworld and pushing them out into more gainful employment. But Yukako Fukushima has one rule before she will take on a mafia client. They must first be interviewed by the police to ensure they've really left the Yakuza.

YUKAKO FUKUSHIMA (translation): I've made so many prosthetic pinkies now, for about 215 former Yakuza. I also make spares for them for the different seasons so I make summer pinkies and spring pinkies.

JUNICHI FUJWARA (translation): She is wonderful. Her work is beautiful. If I didn't have this pinkie I wouldn't have been able to return to ordinary society. I would probably have gone back to the Yakuza world.

MARK WILLACY: These pinkies cost about $1,500 but for gangsters hoping to escape the underworld they're worth every cent. Mark Willacy, Lateline.