JMurone

 It is thought that present-day Homo sapiens have been present in the Japanese archipelago since about 38,000 years ago.

At that time, Japan was not connected to Eurasia by land. The Tsugaru and Tsushima Straits were too deep to become land. Homo sapiens are thought to have arrived in the Japanese archipelago using boats.

Yosuke Kaihu tried an interesting experiment.

Project of voyages 30,000 years ago

source : Base map by Google Earth, Photograph by YUsuke Kaihu.

Track of the logboat colored by day (red) and night (light blue). The circle indicates the area from where the Yonaguni Island is visiblefrom aboat when the weather is clear.

This experimental team led by Yosuke Kaifu speculated that log boats rather than grass or bamboo boats, might have been needed for the Homo sapiens to reach Japan. They therefore built a log boat out of cedar cut down with a stone axe and successfully conducted a voyage experiment from Taiwan to Yonaguni Island in the log boat.

[References]

Kaihu, Yosuke, 2020. Sapiens lands in Japan : Kodansha Ltd.