I know this is late but I went to all three last year so can give a brief overview.
- Independence: The first time you go they have you meet on a street corner outside a metro station. I know that sounds sort-of sketchy but it's fine. The guy will show-up and approach you and ask if you're [your name]. He then walks you back to the shop which is down a dark alley (again, I know that sounds strange, but it's Japan so is fine) roughly a block and a half away. If you go a second or subsequent time you can just go straight to the place and not deal with the pick-up. The guys are only vaguely like what they appear in the photos, by which I mean the photos were not merely smoothed but there was some very creative lighting and - frankly- amazing work by a skilled photographer. No complaints at all by me, just for your awareness. The interior of the shop is the cleanest of them all.
- DG: This one doesn't have en suite showers so you are taken to the room, the guy comes in, you get undressed, then he looks out the door to make sure the hallway is clear and you go to the shower at the end of the hall. Then back again after. Only went here once. The guy was exactly how he appeared in the photo absent minor blemishes (i.e. acne). This is also a studio apparently; if you Google the Kanji character name of a guy there's a chance you might find a movie he's been in. They have a small, but multi-story, building and it appears - though I'm not entirely sure - that the guys are actually working in their call center handling customer service questions (for their video websites) when they're not with a client. At least, when I went there, I entered the wrong floor and walked into what looked like a call center, thought I was in the wrong place, but one of the guys immediately jumped up and politely took me to a room on the next floor up, got me settled, asked who I was there to see, and then went and brought him in.
- TK: I went there twice and saw two different guys. In both cases, the guys were actually better-looking in person than their photos on the website, by quite a bit. Almost as if they did the opposite as what Independence did and ugo-ed them up. This is probably the most run-down -- in terms of facility -- of the three but not awful or anything.
All three had condoms on-site, though they were One Size Fits Small, so you might prefer to bring your own. It seems clear that bare is not an option.