When I was on Facebook, a friend turned me on to his favorite J-pop artists (mostly all girl-bands). They were more recent (and glossier) than the vintage examples here. I haven't been able to access all the Sheena Ringo links (copyright problems apparently), but I much prefer these older tracks--they have more pop bite and more authenticity.

I don't know much about contemporary Japanese music except to know that it's very diverse (and that I don't know much about it). My taste runs toward what might be called indie / analog / post-rock (Yasushi Yoshida, World's End Girlfriend, Mono). Will look for Sheena Ringo and Do As Infinity.