In the morning, I had coffee at Hōkōdō, a historic shop that began selling Uji tea during the late Edo period (1830–1843) and, after the turbulent years of Japan’s opening to the world, became the first coffee shop in Japan to import beans, later restored after its closure, and from there I walked through the former foreign settlement of Kobe, known as the Kyoryūchi in the Meiji era, spending time immersed in the traces of its past. Yet as I was drinking coffee, I recalled that yesterday I had also been researching dōtaku (銅鐸), the bronze bells symbolic of the Yayoi period, and it struck me once again that in understanding the three layers of ancient Japanese history—Jōmon, Yayoi, and Kofun—representing the major ancestral strata of the Japanese people today, one cannot overlook the existence of ancient maritime tribes. Therefore, as part of several ongoing investigations, I decided to shift my means of travel to boats in order to understand the movements of these maritime peoples, drastically altering my itinerary.
In modern times, following the era of rapid economic growth, we have reached a stage of remarkable development where one can travel at high speed almost anywhere using the shinkansen, airplanes, or highways, and many once-isolated islands have been connected by bridges, allowing for car travel as well. In fact, reflecting on my past seven years of research journeys, nearly all of them were by car. However, from the perspective of tracing the movements of ancient tribes, that method no longer seemed appropriate. Upon researching, I discovered that a ferry operates from Kobe Port to Takamatsu via Shōdoshima, so I immediately revised my plans and switched to that route.
The sea route from Kobe to Takamatsu involves a rather large ferry, taking nearly 5 hours. What makes this route particularly remarkable is that, after leaving Osaka Bay from Kobe Port, it passes through the Akashi Strait, connecting Awaji Island and Akashi, then proceeds into Harima-nada, with the old province of Harima visible to the right, Awaji Island to the left, and Shikoku and Okayama in the far distance, entering the Seto Inland Sea. This provides an excellent opportunity to understand both the movements of ancient people and the shifting nature of the sea. In fact, the currents and changes are evident throughout, prompting one to imagine the routes taken by ancient tribes as they traveled across the waters.
This is because, on the main route into Yamato—where powerful tribal kings once resided—via the Seto Inland Sea from Kyushu, it was necessary to pass through Harima-nada, where knowledge of the complex tides was essential. At that time, unlike today, the coastal areas were not heavily developed, so one must erase the sight of modern towns from one’s mind and imagine the scenery restored to antiquity. Remarkably, when viewed from the sea, one realizes that Japan is surrounded on all sides by mountains. Even amid the vast open ocean, the view from the ship reveals a continuum of low to high mountains, with countless small islands scattered throughout, creating a unique landscape across the Japanese archipelago. This is, without question, one of its greatest features, and maritime technology undoubtedly influenced both the migration of tribes and the formation of culture. Yet as island people, we tend to forget this insular character unless we actually leave for foreign lands.