Sex is everywhere in Japan, but most tourists don't see it. They walk past the men handing out tissue packages at train stations, and assume the neon signs in entertainment districts point to karaoke bars. But many indicate hostess clubs, oral-sex parlours, and “soapland” bathhouses. Those tissue packets advertise to men and are also used to recruit female workers.

According to Pink Box: Inside Japan's Sex Clubs (Harry N. Abrams, $45), Japan's commercial sexual-services industry accounted for nearly US$20 billion in 2001. And although these clubs are a cultural phenomenon, they're strictly off-limits to foreigners.

Pink Box captures their inner sanctums in a photographic collection. It's not a coffee-table book you'd want your mother to see. Photographer Joan Sinclair visited over 90 clubs and returned with images of women working in nude theatres, peeping rooms, “touch pubs”, and “image clubs” with elaborately decorated fantasy theme rooms. Examples include a train replica where men pay to grope women posing as schoolgirls, and a department-store elevator, equipped with a mirrored floor and a uniformed, pantyless attendant. In “fashion clubs”, women provide services in true-to-life costumes—such as chain-restaurant uniforms, nurse outfits, officewear—or even dressed as anime characters.

On the line from San Francisco, Sinclair tells the Straight that she first learned of the clubs 10 years ago when she was working as an English teacher in Japan. She returned three years ago to photograph them. “ Pink Box is about the kitsch, the humour, and the over-the-top–ness of the domestic sex industry in Japan,” Sinclair says. “There is a sense of humour about it that's uniquely Japanese,” she says, adding that manga and Japanese graphic art are partly responsible. “There's something in Japanese society”¦that makes these archetypes of everyday life the heart of the role-playing fantasy.”

How did Sinclair gain access to these clubs? She speaks Japanese, and got to know the managers, workers, and customers. Once given permission to shoot, she worked with those who volunteered to be photographed for the book. “It's not an underground industry,” she explains. “They advertise, they all have Web sites”¦they have fan sites for the girls.”

Pink Box doesn't touch on the darker side of the industry: gritty brothels with Southeast Asian sex workers. Sinclair acknowledges that these exist but felt that was a different story to tell. She made the decision to shoot Japanese-style clubs that employ Japanese women. (Prostitution is legally a grey area in Japan, but Sinclair says one criterion they stick to is that they rarely risk employing those under 18.)

The book quotes customers and workers on their motivations. “It would take a year to earn the money for my [Louis Vuitton] purse if I was working in an office,” says a worker.

“All I ask is that viewers not assume that this profession is inherently degrading. It's more complicated than that,” Sinclair writes in the book. “These women are not powerless, they are not on drugs. They have made conscious choices; they have their own dignity.

“The clubs are a reflection of modern Japan, a literate society where the rules are written out, prices are not negotiable, and fantasies are predetermined, prescripted, and prepaid.” Sex and the city indeed.