The first thing I saw was his penis, though it was less interesting than his Yakuza-style tattoos. He assured me these were purely aesthetic, like the silicone rings implanted in his hands.

Despite being the scariest-looking customer in the place, this guy was the most friendly. Apart from the bartender, that is, whose sunny disposition was not dimmed by the heavy metal soundtrack, gruesome decor, and screening of some pretty dark pornography. My trip to Guinea Pig, a BDSM fetish bar in Shinjuku, was a treat by a local expat and friend who’d promised to reproduce his best experiences of the city. It was my third night in the capital, and this was certainly the climax of his personal tour.

I hadn’t planned a pilgrimage to the centre of fetish paradise. I was seeking the usual dose of Japanese pop culture: anime and manga stores, conveyor-belt sushi bars, street fashion and giant pedestrian crossings. Tokyo had other plans.

The city’s sex industry first revealed itself to me with the sighting of a furisode-san (similar to a geisha) in Asakusa. Watching this living doll shuffle off into the night, I remembered the ancient — and now obsolete — custom of mizuage, which sometimes involved the selling of a maiko’s virginity.

There was no trace of this subtlety on the streets of Akihabara — Tokyo’s geek district — where fetishes jetpack into the future. Girls promoting maid cafés were on every corner. They offer an afternoon of being waited on by girls dressed as French maids, who provide grooming services and companionship. Lucky patrons will get a dose of moe, an aesthetic that evokes a mix of intimacy and lust that maid cafés have packaged and sold.

After checking out some of the district’s many adult stores, it was evident that there are few fantasies not catered for. Like Bangkok, Tokyo’s sex industry greets you at the front door. While most cities have their fair share of sex workers and porn shops, Tokyo doesn’t bother hiding these in obscure districts or back alleys.

At its best, it’s refreshing. In comparison, Seoul’s handful of sex shops are overpriced, limited in scope, and often accompanied by a layer of dust and an old guy living in the back. Tokyo’s approach to the sex industry makes it a must for those seeking niche products in accessible locations. Whether you’re in need of man-sized high heels or a Hello Kitty vibrator, the city will provide.

Unfortunately, paedophiles are also invited to this party. Japan has long been notorious for its sexualisation of children (the national age of consent is 13), and nowhere is the Lolita, or schoolgirl, fetish more gratified. I dove into an otaku store in Akihabara seeking manga and gachapon machines, and was instead confronted with kiddie porn. Images of Asian and Caucasian girls aged 12-14 in sexual poses adorned magazine and DVD covers just one corridor into the VIP section.

Unlike the clients at maid cafés, porn shops, and fetish clubs, consumers of child pornography are breaking the law — kinda. A loophole in the current laws regarding child molestation means that owning child pornography isn’t a crime. Those who provide, produce, transport, import, export, or display child pornography in public are subject to a fine and/or imprisonment. Possession without intent to sell or share with others, however, is still legal. The ruling party is seeking to amend the current laws, and they hope a bill will be passed this year. (There’s plenty of opposition, however, as manga and anime artists are claiming it restricts freedom of expression.) Until then, it seems distributors can find ways to avoid prosecution and keep paedophiles satisfied. It took a lot of saké to shake that thought.

This refusal to conform may be part of a national trend. Japan values its sovereignty, and has remained determined to act at its own pace, in its own style. It’s this same exclusivity that has brought us highly influential pop culture and rapid technological innovation, and the sex industry is no exception.