Daikai Jinja
Daikai Jinja is older than Sumiyoshi Taisha. It originally enshrined Watatsumi, a powerful god of the sea who provided spiritual protection for mariners on their voyages.
When empress-regent Jingū ordered the construction of Sumiyoshi Taisha in the third century, she asked the head priest of Daikai Jinja, Tamomi no Sukune, to lead the project. According to the second oldest book of Japanese history, the Nihon shoki (720), Tamomi no Sukune was descended from Ninigi no Kami, the god who is believed to be the ancestor of the emperors of Japan.
Tamomi no Sukune put two of his sons in charge of creating the new shrine. They received the surname Tsumori (literally, “port protector”), and their descendants would head Sumiyoshi Taisha until the religious reforms of the Meiji era (1868–1912).
Daikai Jinja is built in the same style as the main shrines of Sumiyoshi Taisha. It has a simple, straight-lined gable roof topped at each end by a pair of crossed timbers. The building’s columns are painted vermillion, and the exterior walls are white. The entrance faces west toward the sea, and the building itself is divided into two spaces: an outer room and an inner sanctuary.
The two deities currently worshipped at Daikai Jinja—Toyotamahiko no Mikoto and Toyotamahime no Mikoto—are both associated with the sea and maritime protection.