Metal in Japan

Hi!
I was wondering if anyone could recommend either a show, a bar or anything metal in Tokyo or Yokohama. I will be in Japan from March 27th to April 12th and would love to catch a glimpse of the metal culture there!
As an example of the bands like: Opeth, Dream Theater, Iron Maiden, Lamb of God, etc.
But it could be anything, really!
Thanks in advance!

http://www.loft-prj.co.jp/SHELTER/

I've been to some pretty fun gigs here but that was a few years back. You can check their schedule here anyway!

This is not the metal answer you wanted. I think this company is the main promotions company in Japan.

http://www.creativeman.co.jp/

If you click the English part it lists alot of the shows in Tokyo :)

Here's three web adresses you may find useful -

http://www.tokyogigguide.com/


http://rockinncurrent.com/info.html

http://www.antiknock.net