It doesn't help explain anything about roles, but I did some boinking around and found that the director Kohshyoh Ohtake (大竹 幸尚) and the two common artists, Shoji Horikoshi (堀越 昌司) and Katsuya Takahashi (高橋 克弥), were part of the band zbox:
https://ja.wikipedia.org/wiki/Zbox