The Tokyo Grand Sumo Association becomes the All Japan Sumo Association at the instigation of Prince-Regent Hirohito, laying the foundations for the world's sole professional sumo association.

The Japan Sumo Association , officially the Public Interest Incorporated Foundation Japan Sumo Association ; sometimes abbreviated JSA or NSK, and more usually called Sumo Kyōkai, is the governing body that operates and controls professional sumo wrestling, called ōzumō (大相撲), in Japan under the jurisdiction of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT).

Hirohito , posthumously honored as Emperor Shōwa , was the 124th emperor of Japan according to the traditional order of succession, from 25 December 1926 until his death in 1989. He remains Japan's longest-reigning emperor as well as one of the world's longest-reigning monarchs. As emperor during the Shōwa era, Hirohito oversaw the rise of Japanese militarism, Japan's expansionism in Asia, the outbreak of the Second Sino-Japanese War and World War II, and the postwar Japanese economic miracle.

Sumo is a form of competitive full-contact wrestling where a rikishi (wrestler) attempts to force his opponent out of a circular ring (dohyō) or into touching the ground with any body part other than the soles of his feet.