Actually we cannot find any other examples of this unusual computer. We have found very little information. I suspect there are more of these tucked away in some basements in Japan. But since we cannot find any others at this point (2023), we will rate it as exceedingly rare (fewer than 10). And we can hope that the rating changes as more of these surface.
If you know the location of any other of these, please let us know by contacting us at info@EarlyComputers.com.