Battle of Thorn and Bone Pact

In the Republic of 2060 AD, as the population halved, the aura of the earth gradually recovered. On this day, a young man named Hedgehog was riding a mountain bike halfway up the mountain and was controlled by a mysterious force and fell off a cliff. The collision between his body and the cliff caused his whole body to suffer comminuted fractures. At the same time, a magical bone awakened in the soil 100 meters below the valley. This bone accidentally pierced his body in order to save him, and then signed a 100-day contract with him. While gaining extraordinary power, he was mistaken for the incarnation of the Demon King and was involved in the struggle for survival and conspiracy among the spiritual tribes headed by the five spiritual kings, the dragons of the seven Heavenly Kingdoms, the Human Contractor Association... And the Holy Spirit Tribunal. An adventure full of passion and friendship begins...