Two worlds once existed since ancient times. The world of the living, Ushyo, and the land of the dead, Tokoyo. A legendary boundary to forever separate them, The Hell's Gate, has existed since the birth of myths to keep an universal balance. There is said to be four gods that defend it: Seiryu of the East, Byakko of the West, Genbu of the North, and Suzaku of the South. They eternally perform their duty from the shadows of legend and were eventually forgotten by people as time passed.