Here ya go, dude \m/(>_<)\m/
YouTube - -oz- SHANGRILLA live [2009.02.18] A FACT OF LIFE tokyo
YouTube - ネガ - NEO DESTRUCTION PV [HQ]
YouTube - meth. _no one can stop me_
Mind you, -OZ- and meth. don't sound like Lamb of God ALL the time, of coarse, but if I was to compare a Japanese band to Lamb of God, at the moment, those would be the top 3 I can think of right now. \m/(>_<)\m/
I forgot about UnsraW. I don't know about the iTune stores for countries besides Japan and the US, but if you're in the US, you can find some of their music there.
YouTube - UnsraW - Screaming Birthday - -9- (HQ VERSION)