Before Japanese envoys to Sui and Tong Dynasties China left from Suminoenotsu, they gave a prayer to Sumiyoshi Okami at Sumiyoshi Taisha Shrine, and went toward Kyushu through currently called Seto Inland Sea (it was in the Meiji Period when the idea of Seto Inland Sea came out) via Naniwa no tsu (Naniwa Port).
遣隋使や遣唐使は、住吉大社で住吉大神に祈りを捧げた後、住吉津から出発し、難波津を経由して現在で言うところの瀬戸内海（瀬戸内海の概念が生まれたのは明治期である）を九州へ向かった。