What are the restrictions for foreigners drinking and clubbing in Japan?

Question:

I'll be going to Japan for 3 weeks in a few months, while I'm there I really want to experience the nightlife. I don't want to drink if it's illegal, but I do really want to go dance, could anyone please tell me the age restrictions?

I'm 18 and look my age :/

Answer:

" Legal " age is 20. But some clubs won't care. If you just want to have a good time, I'm sure there's places that don't sell alcohol.