As far as I know, the design is from Eastern Asia as a whole and not specific to Japan. 'Steamboats' used to be charcoal fired and it has a channel surrounding the 'stack' which would be filled with soup stock and the diners would be supplied with plates of raw meats fish and veg - tools supplied would be a pair of chopsticks and a small 'fishing' net.
Only meal I've ever had where the soup course is last, but great fun.
Ebay, makes me howl, , RARE? how many of these units do you think mitsubishi made - just for the Steamboat restaurant market ?
bit like an oriental fondue - but none of that ghastly cheese sauce!