Naraku was born fifty years ago. Onigumo, a dying bandit saved by the miko Kikyo, harbored vile desires toward the pure priestess. Those powerful evil thoughts, and the greed they bred, attracted countless monsters. Beguiled by them, Onigumo chose to sell his body and soul in exchange for a strong body and unparalleled power. Unfortunately, no matter how cunning or arrogant Onigumo was, he remained confined by human limitations. He had no idea how powerful a soul could become, or what a human soul meant to monsters.
Among monsters, there were not only high-ranking beings with powerful clans, great strength, and territories and rules no different from those of humans-the Dog Clan, Demon Fox Tribe, Leopard Cat Tribe, Wolf Demon Tribe, Paradise Bird Tribe, Bat Clan, and others-but also monsters so extraordinarily powerful that they lived alone, such as Totosai, the Demon Spirit Great Sage, Granny Medicine, and Swordheart Pavilion. There were also many low-ranking monsters like the Corpse-Dancing Crane and Centipede Woman. Most numerous of all, of course, were the countless monsters beneath even those ranks. These monsters were often born from human malice and resentment, driven by people's powerful desires and the despair they felt before death, only to turn around and feed on humans. These monsters, known as vermin, were relatively weak and had limited potential.
Thus, the intense human malice and desire Onigumo radiated attracted these monsters, drawing them in one after another to devour him. Moreover, Onigumo possessed something none of them had-a complete soul. Not only humans, but all things consisted of one spirit and four souls: the wild soul, peaceful soul, wondrous soul, and fortunate soul. Everything in this world, whether human, animal, or plant, possessed these four souls. Together, they formed one spirit, which became the heart when housed within a body.