Kubo Shoukai, Osaka, 1951
ス保商会
The brand was called the Kongo (金剛号). This one is a bit of a mystery, as the ad shows the company as being Kubo Shoukai, but the book "Century of Japanese Motorcycles" shows a Kongo as being made in 1955 by Fuji Kikai in Tokyo, Either the name was used twice (quite possible), the original company was bought or changed names (also quite possible), or the book is incorrect. Time will tell.
