A frequent visitor to Tokyo for the past 20-plus years asked me whether I thought S/M was on the rise in Tokyo. The answer is both yes and no. Hardcore S/M bars have been discreetly operating throughout that period, but as with all specialty bars, they are controlled by a strict members-only door policy, i.e. no tourists. What has emerged and proliferated in recent years, though, are soft-core, user-friendly S/M theme bars.
Once-regular S/M theme parties held in clubs, however, have declined. Back in the late '80s, the legendary club Gold in Shibaura dedicated one entire floor to S/M, and in the early '90s, Automatix in Shinjuku did the same. But now, except for the annual Torture Garden event -- featuring a hardcore crew of performers from England that fills the house with a who's who of serious advocates (as well as some tourists) -- these events have all but disappeared.
And you will forgive me if I consider most soft-core theme bars to be fake. They are supposed to be. Or, as another expat friend, who suggested a nightcap at Black Rose (one of the most popular such establishments), puts it, they are fun places to take clients because you know they're safe but will also result in a risque story for touting at the office.