I used to listen to a lot of Japanese music. My siter-in-law is from Japan and introduced me to it. Some of it is a little dated now, but it aged pretty well.
Number Girl (remind of a Japanese version of the Pixes)
(live version -
http://www.youtube.com/watch?v=iDov0DF2pZ4 )
OOIOO is one of my all time favourites. The front woman (Yoshimi P-We) used to be in The Boredoms and collaborated with Kim Gordon (Sonic Youth) and formed Free Kitten. OOIOO is one of my all time favourites still. It's an acquired taste though.
Buffalo Daughter is a pretty Japanese rock band too, but most of their songs are in English (or Engrish).