2016 年 29 巻 p. 55-66
The Ookunitama Shrine in Fuchu City, Tokyo, is a shrine that enshrines Ookunitama no ōkami who is the mikogami, the son of Susanoo. The Ookunitama Shrine used to be a shrine in Kokufu（ the capital of the historical Provinces of Japan） that was referred to as Rokusho-no-miya Shrine and Musashi-no-Soja. The Hassaku Sumo Festival is a festival held in the Ookunitama Shrine. The sumo arena in the precincts of the Ookunitama Shrine has a monument built in August 1, 1990. The epigraph says,“ The Ookunitama Shrine Hassaku Sumo is a venerable sumo festival whose Mizuhikimaku curtain was dedicated by the Shogunate for the purpose of encouraging physical activities and which originally started as dedicatory sumo matches to pray for the peace reigns over the land and the huge harvest （of the five grains） in commemoration of the fact that Tokugawa Ieyasu-ko （Lord Ieyasu Tokugawa） made an entry into the Edo Castle in August 1, 1590”.However, currently there is no evidence for the “dedicated Mizuhikimaku curtain” or a document which provides an evidence for the“ purpose of encouraging physical activities by the Shogunate”. Most of the festivals in Japan with the word “Hassaku” are those which have their origin in August 1（ August is“ Hachigatsu” in Japanese, while 1 is“ Sakujitsu” in ancient Japanese） that has the significance related to agriculture such as wish for a good harvest and disaster prevention, or those which were started by the feudal lord who gave a special meaning to“ Hassaku.” The Hassaku Sumo Festival was quite a rare case in that it was said to originate from the commemoration of the triumphal entry into the Edo Castle by Lord Ieyasu Tokugawa. This study suggests that Ookunitama Shrine and the Tokugawa Shogunate continued their close relationship, based on the historical examination of sacred treasures kept in the Treasure Hall of Ookunitama Shrine as well as the history and literature on Ookunitama Shrine. And it presents a possibility that these close relationships may have influenced the Hassaku Sumo Festival. These close relationships can be said to have had sufficient influence on Hassaku Sumo Festival at Ookunitama Shrine to be regarded as originating from the commemoration of the triumphal entry into the Edo Castle by Lord Ieyasu Tokugawa.