What is the story of this aircraft?
It is in fact fake but its most likely loosely based on a real plane. The Russian Kalinin K-7 contains a lot of the same design elements. 


(source)

It appears that the real plane was also boarded from the landing gear area. 


(source)

On a bit of a funny note this article mis-uses the photo you have linked in reference to the Kalinin K-7