Four years ago one of the first presents I brought back from Japan for my Spanish friends was this:
In the middle it is written: 四十八手 (48 arms-hands)
These are the illustrations of 48 Japanese sexual positions, let’s say that it is the Japanese kamasutra. Four years ago I did not think about the origins of these positions and the funny traditional illustrations, but two weeks ago when I when to eat Chankonabe to Ryogoku (Where the most important Sumo stadium is) I found this new catalog of positions in the restaurant’s toilet:
The same word is written in the bottom-right corner 四十八手 (48 arms-hands).
These are not sumo sexual positions these are basic winning techniques used in sumo combats. Both catalogs looked to me pretty similar, the same drawing style and both with the same mysterious word 四十八手 (48 hands-arms). The word 四十八手 started to be used 1000 years ago to talk about all the basic techniques in sumo combats. There were not really exactly 48 techniques, but the number 48 was used because from long ago in Japan it is believed that the number 48 brings good fortune.
500 years later, during the Edo period, the same word 四十八手 started to be used with the sexual meaning. The meaning in the sexual context started to be “all the basic sexual techniques”. In this case there are exactly 48 of them.
Concluding, let’s say that the 48 positions Japanese kamasutra was inspired by the 48 basic sumo techniques. Nowadays the word 四十八手 [しじゅうはって] can also be used in many contexts as “all those tricks known in X”, but it is not a very common word used outside of the sumo world.
Sources wikipedia 1, wikipedia 2 y wikipedia 3.