Note based on 漫画版 日本の歴史〈1〉旧石器時代・縄文時代・弥生時代・古墳時代1 (Illustrated Japanese History (1) Paleolithic, Jômon, Yayoi and Kofun periods 1), Tokyo, 2007, pages 15-20. Translation from Japanese is my own: all approximations are therefore mine. (Note:....) indicates an additional information/clarification not found in the main source that I felt could be useful

Until about 30,000 years ago, the Japanese archipelago was connected a few times to mainland Asia by land bridges (note: depending on the level of water, in relations with glaciation periods): this would notably allow the migration back and forth of animals, and particularly in later days, of big mammals such as Naumann's elephant and Yabe's Giant Fallow Deer as well as mammoths, mooses and elks. People from the continent are believed to have followed such large mammals to the Japanese Archipelago (note: the oldest evidence of human occupation of the Japanese archipelago dates back to around 35,000 BC - although artefacts sometimes much older have been supposedly found, most are of dubious origin and are not currently taken into account)

Japan's first inhabitants used local stones to make their tools, would follow large game in small groups/communities, therefore living a mobile life, essentially establishing camps alongside rivers

In Kamiminochi District (Nagano Prefecture), by the city of Shinono lies Lake Nojiri, which is an important middle paleolithic (around 40,000 to 50,000 years ago - note: archaeological finds date back from 48,000 to 33,000 years ago and men where living in the area from around 40,000 years ago, based on information from the site of the Nojiriko Museum, 野尻湖人の世界 (World of the Men of Nojiri Lake) section) excavation site. Discoveries from the bottom of the lake include manufactured bone implements, wood implements believed to have been parts of spears, animals' fossils including Naumann's elephant and Yabe's Giant Fallow Deer, as well as various stone tools, such as spearheads or tools used to dissect hunted animals (like scrapers), etc In the immediate vicinity were found Naumann's elephant bones which had been broken into pieces and stone tools probably used to that effect, as well as large pebbles. It is believed that this area was where these large mammals were cornered and finished off, before being dissected on the spot; men would have then brought meat and whatever they deemed useful back to their village