Kya.. I can't really get anyone in mind who matches exactly.
JPOP or JROCK?
At first I was thinking of Teppei Koike, but.. I'll think about it! Hopefully I can crack this mystery~
If you get the chance to record it somehow with your camera, that would be great ;o
[EDIT]
http://www.youtube.com/watch?v=zzgIT3V6Q20
INORAN, maybe?
I'm still searching though^^