In both, prospective customers pass an initial vetting to become members, then pay an entrance fee to enter the club.
The club will provide drinks at a bar (often for free), rooms for sex and typically shower facilities.
Entry is denied to the underaged (under 20), male groups, drunk or intoxicated people and, in some establishments, foreigners.
In a high-profile incident in 2004, after porn star and wrestler Chocoball Mukai advertised on his website that he would be performing, the happening bar "Rock" in Tokyo's Roppongi district was raided by police.
[1] Chocoball, who had been caught in the act with another porn star, was later convicted for public indecency and sentenced to a five-month jail term, and the club was forced to shut down.