The owner of a bar in Osaka has found an unlikely ally in the form of Japan's most conservative newspaper after he was prosecuted for "disrupting sexual morals" by allowing his patrons to dance.
Masatoshi Kanemitsu was eventually cleared by the Osaka District Court last week, despite the judge ruling that the regulations were "necessary" and in the public interest.
But the outcome may convince prosecutors to drop other proceedings, particularly given the intervention of the media.
"More people are enjoying dancing as a fitness or artistic activity, and ballroom dance is popular, mainly among the elderly," the Yomiuri Shimbun newspaper said.
"Considering these circumstances, it may be advisable to scrap the regulation of dance halls and dance classes.
"The law should be revised to reflect reality."
The case goes back to June of last year, when 45 officers raided the bar Noon and forced 20 patrons up against the walls.
Kanemitsu assumed the raid was in connection to drugs or perhaps links to the underworld in Osaka - although he strongly denies involvement in either.
He said he was shocked at being detained for 22 days and ordered to post bail of 2 million yen (HK$151,283) for permitting his customers to dance.
"This law is very strange," Kanemitsu said as his court case got under way. "The police wanted me to admit that I had allowed people to dance without a licence and then the police searched my home as well."
The Law on Control and Improvement of Amusement Business was passed in 1948 and requires any establishment that allows dancing to have a licence.
Japan's regulations on dancing venues date back to the early decades of the last century, when dance halls earned themselves a reputation as hotbeds of iniquity.
With the arrival of tens of thousands of US soldiers after the war, the situation got even worse.
Over the following decades, however, the police rarely enforced the provisions.
That has changed in the last two years, with raids on bars in Tokyo, Osaka, Nagoya and Fukuoka.
In the Noon court hearings, prosecutors demanded a six-month prison sentence and a fine of 1 million yen, with police officers giving evidence that patrons were "drinking alcohol and dancing to loud music in dim light".
That was sufficient for the authorities to claim that "hedonistic dancing that disrupts sexual morals" was taking place.