This paper model is a simple JNR Class D51, a type of 2-8-2 steam locomotive built by the Japanese Government Railways (JGR), the Japanese National Railways (JNR), and various manufacturers from 1936 to 1945, the papercraft is created by westjr. There is another version on the site: Simple Japanese Steam Locomotive JNR Class D51 Paper Model Ver.1; and also a The Great Adventures of Kikansha Yaemon D51 Locomotive Free Paper Toy available.
The name consists of a "D" for the four sets of driving wheels and the class number 51 for tender locomotives that the numbers 50 through 99 were assigned to under the 1928 locomotive classification rule. For more information of the D51 please click here.
You can download this paper model template here: Simple JNR Class D51 Locomotive Free Paper Model Download