In Japan, before there were televised broadcasts of sumo tournaments starting in the early 1950s, coverage of the live action occurred on the radio.  We take the internet and television for granted these days, but in the first half of the 20th Century radio and newspapers were the main medium to transmit news and information.  Most of us can conjure up historic images of families sitting around the radio listening to their favorite show.  In Japan, these early sumo broadcasts were familiar to the masses.  In an effort, to place a name with a face, these Stadium/Kokugikan card booklets were produced so fans could follow along a tournament visualize their favorite wrestlers.  These are not unlike the souvenir programs you get at games these days.  Two of these card booklets were issued per year; one showing the wrestlers on the west side of the banzuke, and one showing the wrestlers on the east side.  They issued these in a ten-year span from about 1921-1931.  This one is one of the last ones made and was printed for the March 1931 tournament with the east side wrestlers along with a header cards showing the Kokugikan and the 4 top referees.  Folded up, these booklets measure about 4" x 6", but when it is unfolded, it reaches a length of almost 30".  Each individual card is 1 5/8" x 3.5".  These are hard to find, but one to two come up for auction every year.