@Satoru : It's actually Atsuko Nakajima and Nakamura Kenichiro, both worked on Rumiko Takahashi animated works and copied ehr styled perfectly. Nakamura founded Silence(Sogna) and he drew the storyboards, character designs and helped with the actual artwork back in the day. Surprisingly, he, Nakajima and even Masami Obari(yeah, the mechs are his given how much they look like generic Obari Mecha #878379 and the monster Daimajuu Gekito Hagane no Oni, right down to the way the mechs fight each other) "animated" the thing and had help from Studio Deen as well from some point on during this particular series.