Tattoos have long been linked with the underworld, or yakuza, in Japan, as a mark of gang membership.
But now, a small but growing group of lawyers, academics and other fans of tattoo art are lobbying to save the traditional - if somewhat subversive - industry from being extinguished by a robust interpretation of a medical law by the investigating authorities in Osaka.
The supporters claim that the fight is not just for the freedom to be a tattoo artist, but for freedom itself.
Around two years ago, the Osaka police started clamping down on tattoo artists - who had no yakuza links - claiming that tattoo artists need a medical licence to practise their craft. This sparked the ongoing and watershed legal tussle involving tattoo artist Taiki Masuda, aged 28.
His shop was raided by the Osaka police in April 2015 for purchasing disinfectants from a pharmaceutical company online, as these drugs had to be bought over the counter with verbal instructions regarding usage. The police then charged him with tattooing three female customers in his shop that day.
Mr Jumpei Shirai, Mr Masuda's defence lawyer, said: "The police are effectively classifying the act of tattooing as a medical treatment and Masuda was deemed to have violated the act as he doesn't have a medical licence."
NOT A CRIME
Paying up means acknowledging that tattooing is a crime, and that all tattoo artists are criminals... We are just trying to do the job we love.
MR TAIKI MASUDA, a tattoo artist whose shop was raided by police in 2015 and refuses to pay a 300,000 yen (S$3,750) fine.
If the act of tattooing is forbidden in Japan, it will put Japan at a disadvantage in terms of competitiveness and attractiveness.
PROFESSOR KANAKO TAKAYAMA, an expert in criminal law at Kyoto University.
30 Number of members in the Save Tattooing in Japan group.
15k Number of followers the group has on Facebook.
But unlike five other tattoo artists from an established tattoo shop that the police also clamped down on during the same sweep, Mr Masuda refused to pay the fine of 300,000 yen (S$3,750), arguing that the police have overstretched their powers.
Mr Masuda, who has been a tattoo artist for the past six years, told The Straits Times: "Paying up means acknowledging that tattooing is a crime, and that all tattoo artists are criminals. That just doesn't make sense. We are just trying to do the job we love."
He started a campaign called Save Tattooing in Japan and the group consists of more than 30 members and has more than 15,000 followers on Facebook. Supporters gather at regular events aimed at spreading awareness about tattoo art and what the clampdown could mean for the industry, as well as individual freedom and rights in Japan.
"The police claim that anything which 'could cause danger from the standpoint of public health and sanitation' comes under the Medical Practitioners' Act (1948)," Mr Shirai said. "This puts an unrealistic burden on tattoo artists. If their reading of the law stands, it will spell the end of tattoo artists in Japan."
FROM TATTOOS TO CONSTITUTIONAL RIGHTS
Industry sources put the number of tattoo artists in Japan at around 3,000 to 5,000. The industry is currently not regulated and there is no official registrar of tattooists.
Getting a tattoo in Japan is not a crime, but some companies or government agencies ask their employees to declare if they have any.
Ms Miho Kawasaki, a former editor of a magazine specialising in tattoos, said: "The older generation still views tattoos as a social taboo, but those born after the 1980s would view tattoos as a form of expression and a type of culture."
A 29-year-old male dentist who is a client of Mr Masuda told The Straits Times: "I got a tattoo because I like the culture it embodies. I think tattooing is a type of art, it's strange to think of it as a medical treatment. To say that one has to be a doctor before you do tattoos doesn't make any sense."
According to Professor Kanako Takayama, an expert in criminal law at Kyoto University, the case has constitutional implications.
"If (Masuda) loses the case, it will mean a repression of constitutional rights such as freedom of expression, freedom of thought and belief, and freedom of occupation," she said. "It also violates the principle of no punishment without law of the Constitution.
"If the act of tattooing is forbidden in Japan, it will put Japan at a disadvantage in terms of competitiveness and attractiveness."
As this long-drawn-out case looks headed for the Supreme Court - since its first hearing at an Osaka district court in December 2015 - Mr Masuda's business has been suspended for over 20 months.
Some tattoo artists have been forced to move to other cities to practise their craft, while others risk being criminalised for doing their job. Mr Masuda currently works as a designer to support himself, but yearns to return to his calling as a tattoo artist.
Mr Shirai is confident that he has a strong case against the Osaka police's interpretation.
"The Medical Practitioners' Law should be limited to medical treatment or cure, because that's what the law was meant for."
Most people would agree that tattooing is not a form of medical treatment. But the cosmetics industry also came under similar scrutiny in 2001. The Health, Labour and Welfare Ministry issued a notice that listed "injecting dyes into the human skin with needles" as a medical practice.
It is common for tattoo artists to practise on themselves or on willing family or friends first, before taking on paying clientele. Mr Masuda himself has used his own legs to practise his tattoo art.
"This notice was in relation to cosmetic surgery such as laser hair removal and permanent make-up, such as eyebrow embroidery. But the point is that the court has the power to interpret the law, not the administrative authorities such as the police," Mr Shirai emphasised.
So why are the police clamping down on an industry that dates to as far back as the Edo era some 400 years ago?
Kyoto University's Prof Takayama described what is happening with a quip.
"Recently, the number of criminal offences in Japan has dropped," she said. "Since the police want to keep their 'business' and exert power, they started clamping down on conduct that has not been regarded as a criminal offence."
Given the tattoo industry's shady connections, it could have seemed like an easy target.
However, Mr Masuda explains that all his clients had to sign a declaration that they have no connections with the yakuza, and he also urges them to consider carefully the tattoo that they want to have.
"Often, I will advise clients to consider very carefully before tattooing their boyfriend, girlfriend or spouse's name, because situations may change. I remind them that getting a tattoo is not something to be taken lightly."
Ms Kawasaki, the former magazine editor who is now a freelance editor and writer, suggests that it may be a good idea to regulate the industry with a registrar of licensed practitioners based on a set of safety standards and procedures.
"This should involve consultation with practising tattoo artists and may or may not require national regulation. If such a system is introduced, it would be the first of its kind in Asia, and I hope we can set a good example for other countries," said Ms Kawasaki.