Going straight after a lifetime spent as a member of Japan's feared yakuza organised crime mobs poses a number of challenges. Chief among them is what to do about the fingers you chopped off.

For one reformed wise guy, the answer lay in thousands of dollars' worth of prosthetics crafted to look exactly like the three of his digits he hacked off to appease his one-time bosses.

"You see how real these fingers are?" said Toru, 53, proudly showing off his artificial body parts -- both little fingers and his left ring finger.

"There was only one time that anyone ever knew they were fake. She was an old lady in her 70s. I told her I was injured in a factory."

Like the Italian mafia or Chinese triads, yakuza gangs engage in activities ranging from gambling, drugs and prostitution to loan sharking, protection rackets, and white-collar crime.

The gangsters in Japan, who number 63,200, have historically been tolerated by the authorities, and are heavily romanticised in popular culture, spawning a vast catalogue of manga comics and movies.

Observers say the strict code of honour of the yakuza, passed down from the samurai warriors of the 17th and 18th centuries, is largely gone and many are little more than brutal criminals.

But even in the mob, Japan's rigid societal rules play out.

This means your peers are always supposed to look out for you and protect you. Likewise, it means you have to look out for them.

Toru -- not his real name -- used to make his living offering "protection" to the bars and clubs of Tokyo's Kabukicho red light district.

He was a success, making sure the rival gangs stayed off his turf and keeping the money flowing up to his seniors.

But then one of the men in his gang -- a "brother" -- fell foul of the strict prohibition on stealing and drug use.

To assuage his boss's anger and prove the group was truly penitent, Toru sliced off the top of his left little finger.

Unfortunately, someone got the group into trouble again a short time later, and Toru had to take the knife to the second joint.

"The first joint of a little finger can be sliced easily," he said. "You tie the bottom of it with thread tightly and put your body weight on a kitchen knife. But the second joint was tougher than I thought."

Luckily, there was a brother to hand, who could stand on the knife and slice through the knuckle.

The loss of the tip of the pinkie on his right hand was his own fault -- he got drunk and started throwing furniture around in a bar.

Unfortunately for him, the bar belonged to a friend of his boss. Out came the kitchen knife again, and off came the top of his little finger.

But his fourth amputation bore a whole different significance.

"I met my wife," he said. "I wanted to marry her, but she said she couldn't possibly marry a yakuza guy. So I quit."

Of course, you can't just resign from the yakuza. You need to offer a sacrifice. A ring finger, for instance.

"I tried to do it as usual with a kitchen knife, but the blade didn't go through because of the muscle. I had to ask a brother to take a hammer and a chisel to lop it off," he said.

"Oh, it was painful."

Where once the missing fingers were badges of honour, proving to fellow gangsters that Toru was loyal, hard-working and prepared to make sacrifices, they now worked against him.

Life as a "katagi" (civilian) is tough when everybody knows how you used to make your living, with respectable companies unwilling to be connected to the yakuza.

The only solution is to get your fingers back.

That is where prosthetics specialist Shintaro Hayashi came in, crafting three silicone fingers, complete with the creases and lines of a natural digit.

His works are so delicate that he even implants individual hairs taken from his subjects' hands and arms to give each finger a really lifelike look.

"I think of myself as being like Geppetto," he said, referring to the woodcarver who created Pinocchio.

"My job requires not only knowing the person well but also injecting his or her personality into the parts," he said, adding that he keeps a photo of his client on his desk as he works.

The bulk of Hayashi's clients are people who have lost hands, feet or ears in accidents, or are born with something missing, but around five percent are former yakuza.

Making a mould for the silicon casting is expensive -- around 300,000 yen (about $3,000) for one finger -- but it means the prosthetics are easy, and relatively cheap, to replace when they look tatty or worn.

"For me, these fingers are consumable items," said Toru. "I have to renew them every three months."

And they have been well worth the initial outlay, allowing him to build a house renovation company that does legitimate work.

"I now run two outlets for my business, making about 300 million yen a year," he said.

Asked why he granted the interview, Toru has a quick and easy answer -- he wants to show yakuza stuck in a life of crime that there is another way.

"They could do well if they work hard, even if they have lost some of their fingers.

"Life is much easier this way."

Japanese Yakuza