Probably since the birth of human beings, obsession has existed in the brain, and this obsession is sometimes taken by the monsters in the underworld, the fierce ghosts. The incarnation of justice in the Netherworld, the Netherworld Swordsman, rushed from the Netherworld to the human world to fight against the fierce ghosts. But they found that human obsession will never disappear no matter how many years go by, and their lives are limited, so they left their swords in the world and passed them down from generation to generation by outstanding people. In this way, this war between the Nether Swordsman and the Fierce Ghost in the human world has lasted for thousands of years, and will never stop in the future...