Sex workers in Osaka will be shown the red light as the city seeks to clean up its image before hosting world leaders for the G20 summit in June.
All 159 members of the Tobita Shinchi association, which represents businesses in the red-light district, will close their doors during the Group of 20 meeting to avoid causing "disruption," an association official told AFP.
"Because the summit is a huge event, we thought that even a minor bit of trouble between our customers could be a source of disruption, and have decided to close our operations voluntarily," he said.
Trouble between customers tends to break out in part because of alcohol consumption in the district, he added.
Tobita Shinchi was once known as the largest neighbourhood of licenced brothels in Japan, but to circumvent anti-prostitution laws, many establishments now operate as 'Japanese-style restaurants'.
The association took a similar measure in 1995, when Osaka hosted the Asia-Pacific Economic Cooperation summit, with some but not all neighbourhood businesses closing during the meeting, the official said.
Japan will host the G20 summit in Osaka on June 28-29, with US President Donald Trump and China's President Xi Jinping among the world leaders expected to attend.