japan: i want to know how to survive in the nightlife

Below is a quote taken straight from the Get Hiroshima map/info guide I got at the tourist info centre at Hiroshima:

Warning!!!
Dancing in a club after 11pm is technically an illegal act in Japan, and while there are any number of places where you can dance till dawn local police have been enforcing this archaic law. In a recent raid, involving over 50 police officers, Japanese and non-Japanese were separated and all foreigners’ IDs were checked. While such raids are rare, we advise visitors to carry their passports, or risk being escorted back to their hotels to have their belongings searched.