The deity of Sumiyoshi, one of the more famous in Japan, is a composite of three separate deities: Uwazutsu no o no mikoto 表筒男命, Nakazutsu no o no mikoto 中筒男命 and Sokozutusu no o no mikoto 底筒男命, all of whom came into existence when the progenitor deity, Izanagi no mikoto伊弉諾尊, purified himself by bathing at Awakihara 檍原 in Tsukushi 筑紫 after visiting his wife Izanami no mikoto伊弉冉尊 in the Land of the Dead. Originally a kami of purification and the sea, Sumiyoshi also took on the mantle of patron deity of waka poetry, and is now venerated as a fosterer of industry as well. His main shrine, Sumiyoshi Taisha 住吉大社 can be found in Settsu in modern Osaka, and on the web at http://www.sumiyoshitaisha.net, although there are more than 2000 branch shrines throughout Japan. Sumiyoshi also enjoys a second incarnation as the kami of medicine, healing, carnal lust and dissipation, and is venerated as such in Uji 宇治 near Nara 奈良, accompanied by Hashihime 橋姫, goddess of bridges and lust.
The deity enjoyed close relations with the imperial family, providing Empress Jingū 神功 (consort of the 14th Emperor, Chūai 仲哀) with a magical jewel to calm the seas for her invasion of Korea and, fictionally, aiding Genji during his soujourn at Suma 須磨and paving the way for his return from exile. Gotoba’s poem, then, is a lament that Sumiyoshi has not been able to aid him, as he aided Genji.