Well here's a new one on me!
I noticed this on another WWI website and it rather caught my attention.
(It was posted no details of where the pic originated or who owned any copyright, so I guess it's OK to pass it on here.)
A further search of the net found no additional photos, although I see one brave soul has started to scratchbuild it around a 1/72 Roden Nie fuselage.
The oic is titled Nie 24/Na Ko-3 with negative aspect ratio 'wings' - 1920s experimental Japanese project.
I wonder if it ever flew (and in which direction?) - assuming they could find some brave soul to fly it!
Sandy