During the Late Pleistocene, the Japanese archipelago formed a long peninsular projection on the northeastern Pacific Rim, encircling the much-reduced Japan Sea. As the evidence for human activities on the vast lowland plain which is now the Yellow Sea has since been obliterated, the archaeological data from some 5,000 Late Palaeolithic sites from the archipelago provide us with information about the people who lived on the very edge of the Eurasian continent facing the North Pacific.

They may have had some form of watercraft as early as 30,000. The results of various physico-chemical analyses indicated that obsidian flakes recovered from a number of Late Palaeolithic and Jomon sites in and around Tokyo came from Kozushima Island, which is unlikely to have been connected to the main Honshu island even during the Last Glacial Maximum. While direct evidence of subsistence activities is rarely preserved in the volcanic soils of the archipelago, the Palaeolithic inhabitants of Honshu who made repeated trips by rafts or boats to Kozushima for obsidian procurement could very well have utilized the marine resources for subsistence purposes.

Direct evidence of the use of fish is found at the Maedakochi site near Tokyo, dated to about 11,000 cal. BC, associated with early pottery and over 2000 slender bifacial foliates. The disproportionally large number of salmon teeth to a small of number of vertebral fragments, as well as the charred condition of the bones, suggest that the site was a specialized fishing camp, where the seasonally abundant resource was harvested and processed for storage.

By 8,000 cal. BC, when the use of ceramics are widespread throughout the archipelago, clear evidence of maritime adaptation is present in numerous shell middens, containing fish hooks and fish bones. The presence of such species as tuna and bonito suggests deep sea fishing from a boat, although the actual remains of navigational equipments are not known until Early Jomon times about 5,000 cal. BC.