GETTING tattoos in Japan is becoming a popular activity among Australian travellers. But hardly anybody realises that popping into a tattoo parlour there is actually illegal.

That's the upshot of a landmark court ruling in Osaka this past week which has all but banned tattoo parlours in the country.

In Australian tourism favourites like Tokyo, Osaka and Kyoto, dozens of tattooists sketch ink designs onto tourists daily, operating their businesses openly despite a Japanese law which dictates tattoos can only be done by doctors.

Last week, an Osaka tattooist was found guilty of breaking this rarely-enforced law, which threatens to bring down the country's massive tattoo industry.

If you are planning on getting a tattoo on your next holiday to Japan, you won't be punished yourself. But you will encounter some nervous tattooists fearful of becoming the next artist to be prosecuted as a result.

When I visited two tattoo studios in Tokyo in June, staff members were well aware of the high-profile court case in Osaka but none predicted the guilty verdict handed to tattooist Taiki Masuda.

Mr Masuda, 29, was given a fine of 300,000 yen (A$3,400) which was later halved on appeal, and he intends to launch a legal challenge against his conviction.

His crime was performing tattoos without a medical licence - this law targets the artists rather than their customers.

Tattoos were banned in Japan from the late 1800s to the 1940s and then soon after the end of World War II the country loosened the law by introducing the requirement of a medical licence.

The world is filled with peculiar old laws which are rarely, if ever enforced, and for decades this was one such rule - hundreds of tattoo shops operate in prominent locations across the country despite it.

Tokyo, in particular, has become a popular destination for tourists to get tattoos, with both of the artists I visited saying they get many clients from Australia, Europe, the US and elsewhere in Asia.

But the shockwaves created by this week's verdict - which means most tattooists in Japan are now at risk of prosecution - was so severe that those same artists I visited declined to make comment to me this week.

They feared that by speaking out against the tattoo laws they would place a bullseye on their heads.

Not all of Japan's tattooists have the same concerns. Hideo Kuboki, from Zen Tattoo Studio in Tokyo, described Japan's tattoo law as "strange". He told me was it old-fashioned and made no sense in modern Japan, where so many people now had tattoos.

Mr Kuboki said he was worried about the impact the ruling would have on his business.

Some other Japanese artists don't have the same sympathy for Mr Masuda. Jiro Nakano, from T.F.T.D. Tattoo Shop in Tokyo, said Mr Masuda and other Japanese artists who used modern tattoo guns were not "real" tattooists.

He argued the only authentic artists were those who practised the traditional Tebori style of tattooing, which is done by hand using a needle attached to a wooden or metal rod.

The ancient art of Tebori is reflective of the curious position tattoos hold in Japanese culture. Despite body art dating back 2000 years in Japan, tattoos carry a heavy stigma. Whereas in Australia body art is widely accepted, in Japan it has negative connotations, some of which is linked to the Yakuza, the infamous organised crime gang which wields enormous power in Japan.

While many everyday Japanese people now sport tattoos, they previously were associated primarily with Yakuza, who are famous for their elaborate body art.

As a result, many public spaces in Japan such as gyms, pools and saunas do not allow people to display their tattoos. Body art must be covered up so that other guests are not intimidated by the presence of a possible Yakuza.

Many inked-up Australian tourists would have been asked to follow these rules at some point during trips to Japan.

The owner of Tokyo tattoo parlour Chunky May May, who wanted to be known only by her first name May, said she had never had signage outside her shop because she did not want to attract Yakuza customers or negative attention from neighbours.

She understood why some Japanese people did not like tattoos, but argued that the medical practitioner law was unjust. May wondered whether the law was designed to restrict the creativity of Japanese people and cultivate an unthinking populace.

It remains to be seen whether the historic court ruling in Osaka will lead to tighter restrictions on the public display of body art.

In the short term it seems likely that tattooists in Japan will want to keep a very low profile. May said that could include turning away tourist customers, who could draw more attention than a Japanese client.

And with Japan set to be flooded by tourists for the 2020 Olympic Games, the country's strict tattoo law will come under heavy worldwide scrutiny.