That's no cinema poster, but an ad for a pachinko (Japanese pinball) machine with a BACK TO THE FUTURE theme. These posters hang outside of pachinko parlors that are everywhere in Japan so you can safely assume it was printed in large numbers. Based on the artwork I would assume it is not from the time of the original release of the movie but was issued much later. These pachinko posters are far less valuable than original cinema release posters. So unless you are a die-hard fan of the movie or you can get the poster for a cheap price, you might want to pass on it.
Armin
