If several people here want and actually do go to the (same) concert it would be nice to meet up somewhere.
I think hotels shouldn't be too much of a problem, you don't have to stay in the ultimate vicinity, even if it's an hour by train or so, it shouldn't be much of an issue. Additionally these concerts seem to be in the big cities (Osaka, Nagoya and Toyko for the 9th anniversary concert iirc). My main concern is getting the ticket in the first place. But i already talked to my Japanese teacher and she said she'd help me if necessary. And then there is the "issue" of going to Japan twice in one year, since i'm going for this years hanami season.
I wonder if i can convince someone to come with me to the concert, or to japan for general for that second time (i doubt the friend i go with in spring will come twice). And if all fails, i would also go alone.