I haven't shown many lately, but there are several unidentified Japanese cards in my collection. Here's one of my newer ones.
The backs have the same usual stuff as found on other menko, but the order is somewhat unique. The menko number is in the middle, with the janken symbol at the bottom and a robot cartoon above. I'm not sure if the other cards I saw had robots or some other art.
Given the quality and the card stock, I would guess this is post-1960.