Bars/clubs in Tokyo for younger people?

[mishkin]

So I'm going to Tokyo with some friends in July, we're trying to find somewhere to go out one night.

I'm a 20 year old female, but among the people travelling with me is a 19 year old male. I guess clubs are off the agenda if they check ID strictly.
(Though we might leave him at the hostel if you have any good suggestions)

Any recommendations for good bars in Tokyo?
Somewhere preferably not too classy, for younger people and not too expensive?

[BackDoor_Man]

There are places called "Live Houses" all over Tokyo, they are cheap, fun and every now and then there is good music! And they do not ask for Id, but if you act like fools, they will show you the door. I would recommend "Jirokichi" (always good music), in Koenji, on the Chuo line (orange train out of Shinjuku, less than 15 minutes, first stop after Nakano)). Cover charge usually 1,500 yen and a drink, 3,500 yen or more if the band is really good! Many famous Japanese musician started there and play there.