The international-release promotional poster for The Humanoid was painted by renowned Japanese artist Mr Shusei Nagaoka.

Nagaoka has worked in the field of movie illustration, but is most commonly associated with his iconic music album covers of the 70s and 80s. He won Rolling Stone magazines best album cover of 1976, and many of his best known works contain a sci-fi influence. He is probably best known for his work with American R&B legends Earth Wind and Fire. His cover of this album is titled Helios, an obvious Humanoid reference, and its interesting to speculate if the movie influenced the artwork, or vice-versa.
Click Humanoid poster images to enlarge

Many thanks to Humanoid fan Kenju Shimomura for the information. masterpage