Possibly Japan's most accomplished and well-respected band of the 90s was the Boredoms. They weren't a novelty group like Guitar Wolf or Melf-Banana (I don't care what you have to say ... I can't take a group that makes feature-film-length music videos with robots and Godzilla-look-alikes seriously), and they actually got quite a bit of buzz over in America. Their most recent drummer, Yoshimi P-We, started her own band, OOIOO, soon after she appeared in a photo shoot with three of her girlfriends for a fictitious band. They took the photo-shoot seriously, I guess, and released a damn good avant garde record, Feather Float.
The band's sound is sort of hit-or-miss, however. And isn't all avant garde music like that? Avant garde music is never really a trend because that is contradictory to its avant garde status ...
Anyway, they combine a bizarre tribal, organic drumming technique to a post-rock/punk style, making for some potnetially interesting rhytms, if nothing else. Their new album (although it was released in Japan in 2000), Gold & Green, is their most accesible, as it seems to have more structure to it. Yoshimi actually tries to be a songwriter on this record ... she doesn't just shoot for the spontaneous.
Also, the record features Seiichi Yamamoto (also from the Boredoms) and ... (gasp) Yuka Honda, the less public half of now defunct Cibo Matto.
I really enjoy the album, and recommend buying it or downloading it or something ...
You can hear some samples here.