Welcome to everyone finding my blog via my column at Tinymixtapes. A couple posts of particular interest:
Japanese hip hop prehistory: Jagatara
The Sumo Tapes: Ganja, Rappers, and Big Fat Asses
You can also find a ton of good stuff just by following the "Japanese hip hop" tag, conveniently attached below.
For those headed the other direction, here is the most recent Japan the Beats at Tinymixtapes, about Origami, nostalgia, and indie-farm fashion.