The plaintiffs said they signed up for a program to align their teeth using mouthpiece trainers, in exchange for providing details of their care for public relations purposes. Instead, they said they ended up owing money for incomplete treatment.
The Dental Office X chain operated clinics in cities across Japan, including Tokyo and Fukuoka.
The plaintiffs' lawyers claim that the victims signed contracts between 2020 and 2022 after the company asked them to become model cases. They said the company told them that they would receive compensation which would offset the treatment's costs to make it "effectively free."
But the company stopped paying the compensation, and people were left with huge loans they had borrowed to have their teeth fixed.
Then the clinic closed most of its outlets, leaving the plaintiffs halfway through their alignment procedure. They claim this resulted in dental and other health problems.
Plaintiffs in a Japanese dental dispute face ongoing health problems
Some of the plaintiffs met with reporters on Tuesday.
One woman said that she had her teeth shaved down for the treatment, making them sensitive, and that she is worried about this.
Another said she could not have handled fighting the company by herself, but now that she is no longer alone, she wants others to share their wisdom and fight together.
Japanese dental dispute plaintiff says 'treatment was offered effectively free'
Plaintiff Sekiguchi Arisa said she signed a contract for treatment two years ago, after she learned from social media about the clinic offering people orthodontic procedures in exchange for providing details of their care.
Sekiguchi took out a loan to pay the clinic the full 1.87 million yen in treatment costs, and agreed to repay 50 thousand yen a month for three years.
Meanwhile, she was supposed to have received 50 thousand yen a month over the three-year period as the clinic collected data on her care.
At first, she said the treatment and the compensation all went well. But in March last year, she suddenly received a document online from a company whose name she did not recognize. It said compensation could not be provided for the time being, because the company's overseas assets had been frozen due to Russia's invasion of Ukraine.
She said she became suspicious at that point, and realized she had become ensnared in an apparent fraud.
After her payments stopped arriving, the clinic suddenly closed and her treatments stopped. She said she faces loan repayments of around 11,000 dollars.
Sekiguchi said she now has trouble opening her mouth, her teeth are chipped and she refrains from smiling to avoid showing her teeth. She called her situation "unforgivable," and said that simply getting her money back "won't set things straight."
Japanese dental dispute plaintiffs gather through social media
Sekiguchi said she did not know what to do at first, but then she searched social media and discovered that many other people were in similar trouble. She anonymously began a group chat to share information.
As the number of online participants increased, some suggested filing a lawsuit together. Many were struggling to repay their loans and could not afford to file a suit on their own.
Sekiguchi said she was told filing a suit by herself would cost at least 1,400 dollars, which was too much for her. She thought that if people joined to file a suit together, they could share evidence and reduce the costs for each person.
However, some were fearful about falling for another apparent scam after what they had experienced. They worried about whether they could trust Sekiguchi.
So she decided to reveal her name and face, and called for her fellow sufferers to join together in a lawsuit.
About 300 people signed on to be plaintiffs in the suit, with each paying about 360 dollars.
Expert: Japanese dental dispute lawsuit may open new possibilities for victims' relief
Lawyer Sasaki Yukitaka said cases in which victims connect with each other and then join to file a lawsuit are rare in Japan.
Sasaki said many victims of previous consumer fraud cases had no connection with each other, so people often gave up because they did not think they could do anything by themselves.
Lawyers or others are typically the ones who find victims and persuade them to take part in joint lawsuits, rather than the other way around.
Japan established a system in 2016 allowing consumer groups certified by the government to file lawsuits and receive relief on behalf of victims. But groups have said that using the system is difficult unless compensation in a case is all but assured.
Sasaki said that the dental dispute case made him hopeful of new possibilities to provide relief to victims, as strangers connected with each other through social media and agreed to file the suit together.
Japanese dental dispute defendant denies responsibility
The Granshield, the company that signed contracts with the plaintiffs, replied to NHK in writing in late April. It said it plans to pay holders of valid contracts, but that it will carefully consider what to do with contracts that appear to be dubious. It said that concerning treatments, the dentists were entirely responsible, so it could not comment.
Dentist Ito Takehide, believed to have been in charge of orthodontic treatment at the clinic chain, is also named in the suit. But he said that he opposed the move to offer virtually free treatment, and he claims that he severed all ties with the company.