Kev, I saw Ryokuchi and Birushanah (pretty sure they're both Osaka based) fairly recently in Melbourne. Sweet bands, Ryokuchi played as a two pece and were thrashy as fuck. Some mean droned out wierd sounds from that bass.
Birushanah were awesome, some crazed Japanese steel percussion along side some crushing riffery..I think one member was in corrupted..

Seen these guys?

Seen both of these bands. Shibata, the front man from Birushanah played bass in Corrupted for a little while a few years back. Good bloke with some great tattoos. Simon from Dad They Broke Me (Melbourne) used to do vox in this band when he was living in Japan. Birushanah are definately a powerful tribal/sludge group.