By Jonathan Head
BBC News, Tokyo
Japan has started applying stricter regulations on the tens of thousands of Filipinos who come to Japan on so-called entertainment visas.
Tokyo's bright lights are a magnet for immigrants
The new measure is a response to criticism of Japan's failure to curb human trafficking.
Many Filipinos who arrive on such visas end up working in Japan's sex industry.
However, organisations supporting overseas workers from the Philippines have expressed concern over the loss of earnings caused by the new rules.
The Philippines government is currently negotiating with Japan to allow more of its nationals to work in other fields in Japan.
Between 60,000 and 80,000 Filipinos arrive in Japan every year on entertainment visas.
This is a euphemistic description for a process whereby most are directed by agents in both countries into Japan's extensive sex industry.
The lucky ones end up in upmarket hostess clubs and bars, where they may be well treated and earn good money.
The less fortunate find themselves working as prostitutes, subject to abuse and given no legal protection.
Now the Japanese government is trying to clean up the country's image after criticism by the US state department last year over its failure to control human trafficking.
It wants to cut the number of entertainment visas issued to Filipinos to just 8,000 a year by imposing much stricter requirements.
From Tuesday, applicants will have to provide a certificate showing they have studied some form of performance art for two years.
However, the new policy is not popular in the Philippines.
Groups who support overseas workers say most of those who go to Japan on entertainment visas are not abused and their families rely on the earnings sent back.
They complain that it contradicts the Japanese government's promise to consider opening up to more foreign labour.
The Philippines government is currently pushing to get more access for Filipino health and care workers.
But the negotiations have dragged on for months and so far, Japan is only talking about allowing just 200 highly-trained applicants into the country.