According to this article working girls are exempted from new curfew.
Quote:
...Tatsuo Mizuno, head of child welfare at the Tokyo metropolitan government, says the regulations will not restrict freedom of movement.
"Teenagers who have good reason to be at these places during the curfew, say for work, will not be affected," he said.
"Tokyoites of all ages have lots of reasons to be out late at night...
Tokyo's mission to clean up its streets of shame
Justin McCurry in TokyoThursday February 5, 2004 / The Guardian