Quite the trip. The mangaka must have read a lot of the most far out stuff in the French magazine Metal Hurlant (Heavy Metal Magazine was the American offshoot). The art, which is very good, is heavily inspired by MH founder Jean Giraud (Moebius). Just look at the contour hatching techniques. Moebius is even better though.
I wondered if the mangaka is related to the late great Koike Kazuo (one generation older), but it seems that quite a few with that name has been dabbling into manga, so it's hard to tell.