(image from JAN)
Senior members of the Japan Avalanche Network have posted their report here
Summary:
Size 2.5
34 degree start zone
North aspect
Crown wall between 10 and 150cm high
Weak layer was a 2cm thick layer of 1mm facets
2 dead, 3 injured, 6 in the party. More/comment about 20101130 Tateyama Avalanche