The clubs my mates and I went to were as hood as hell. Way too hood for their own good. I've been to some pretty grimey and thugged out clubs before, but the music they spun didn't have shit on the clubs in Japan. They played so much gangsta rap and hip hop that it was unreal. From the popular cuts to the most obscure gangsta rap ever. I don't mind rap. But I can't dance to it for 4 to 5 hours straight. There's only so much 2 stepping and leaning I can do. I love R&B and a bit of commercial pop - plus this is the music that gets girls going. So most clubs in Japan you'll find the dudes will swarm the floor, whilst girls are sat down or have their backs on the wall waiting for something a bit lighter they can work the waist to.
Clubs in Japan are varied too. No two clubs are alike and you quickly find the kind of spots you'll want to visit again and those you don't. A couple of clubs my mates and I went to included Sam & Dave's: a chain of clubs in Osaka, Pure: a nightclub in where you pay about 4000 yen and get free drinks all night and a couple of bars / clubs hybrids where people run rampant drunk.
Clubs in Japan are great places to go if you're into clubbing. I'm not sure what I expected clubs in Japan to be like, but they're pretty similar to the clubs I check out in London. What I loved about the clubs in Japan was how people were towards me. The majority of people in Japanese clubs are really up on the Western ways, so they tend warmer towards you than some of the folk you pass on the streets during the day - sometimes to the point of fascination. You're never shy of having a Japanese person in a club want to hop in a picture with you, which was cool and a nice reminder that Japan isn't this western shunning, cold place that many make it out to be.