Isekai - Pre story

A dense, untamed Mesolithic forest stretches along the banks of a mighty river, dominated by ancient oaks, Scots pines, and a humid climate. In this primitive world, modern animals are nonexistent; the fauna is dominated by their colossal wild ancestors: ancestral aurochs, giant deer from the Ice Age, and the fearsome cave bear. At the water's edge, beside the still-warm ashes of a rudimentary hunter-gatherer camp, lies the scene of a tragedy: disturbed earth, abandoned flint tools, fresh bloodstains, and the deep footprints of an extinct beast that devoured the original hunter. The atmosphere feels hostile, mystical, and charged with tension, illuminated only by the sunlight filtering through the thick foliage.

The fauna of this period knows neither domestic nor modern species, but rather their imposing wild ancestors that dominate the dense vegetation: colossal aurochs—the fierce and untamed ancestors of bulls—graze near the water alongside giant deer and elk with massive antlers, while in the shadows lurk large predators such as the cave bear, primitive lynxes, and packs of gigantic gray wolves.

The humans of this period were hunter-gatherers of the Homo sapiens species, genetically known as Western hunter-gatherers, characterized by a striking physical combination: dark skin, dark hair, and striking blue or green eyes. Of wiry build, honed by a life of constant movement and survival, they dressed in tanned animal skins tied with sinew and adorned with teeth or shells. They lived in small, nomadic family bands, demonstrating absolute technical mastery over their environment by crafting fine flint tools, yew wood bows, and lightweight huts on the water's edge, maintaining an instinctive and precarious connection with a wild world they had not yet attempted to dominate.

The resources available in the Mesolithic environment are characterized by being 100% organic, of natural origin and oriented towards basic sustenance and the manufacture of rudimentary tools:
Raw materials for tools: Abundant flint for carving microliths, arrowheads, scrapers and knives; quartzite and river rocks for hammerstones; tough wood (such as yew, oak and hazel) for making bows, arrow shafts, spears and dugout canoes; and deer antlers or thick bones for making harpoons, fishhooks and needles.
Food and nutrition: Great sources of protein from hunting aurochs, deer and wild boar; abundant fishing of salmon, trout and pike in the rivers; intensive harvesting of nuts (with the hazelnut as the star resource due to its high caloric content and ease of preservation), as well as wild berries, edible roots, mushrooms, honey and freshwater mollusks.
Uses for shelter and clothing: Thick mammal hides and skins for making protective clothing and coverings for huts; dried tendons and guts used as strong ropes and sewing thread; animal fat used to waterproof materials or fuel primary lamps; and ashes along with pine resin to make powerful natural glues.