Japan Times and Advertiser, Tuesday 13th May 1941
(Evening Edition Page 4)
Services for Sumo Fans
In the pandemonium that reigns throughout the Kokugikan
arena immediately after every important bout, it is an impossibility to
hear the decision and other important details of the results, especially
when one is seated way up in "nigger heaven". Hence, for the use of these
customers, special audiphones have been installed at a minimum charge of
30 sen per day.