It is said to have been built by order of Empress Jingu as a shrine guarding the entrance to Osaka Bay. The name is said to have come from the fact that this shrine is the guardian deity of Izumi Sakai Minami-sho and its gates face the sea. Alternatively, it may be that Shiotsuchi-no-Oji-no-Kami, who is said to have been enshrined by Empress Jingu, had never spoken before, but finally opened his mouth after the Empress offered offerings. Shiotsuchi-no-Oji-no-Kami is also known as the "inner sanctuary of Sumiyoshi" due to its close connection with Sumiyoshi Taisha Shrine. In 1113, at the end of the Heian period, when the shrines of the three villages of Kaiko, Kido, and Hara were merged, it became the guardian deity of Sakai. Furthermore, until the Edo period, the shrine was home to a temple called Nenbutsuji, built by Gyoki in 746, and remains affectionately known as "Otera-san" (Great Temple). The shrine's treasures include the Great Temple History Scroll, the collection of poems written by Emperor Fushimi, and the short sword with the inscription Yoshimitsu, which are designated as Important Cultural Properties. At the Hassaku Festival held every year in mid-September, Sakai's oldest futon drum is dedicated.