Soukaigi takes place in December 1998. An explosion on Mount Fuji, as well as in other areas of Japan, has killed 14 percent of the nation's population. The explosions have caused several fireballs to unite into a gigantic pillar of fire 150 kilometers in height and 10 kilometers in width. Stone pillars known as Gallan have also appeared throughout Japan, and ghostly demigods known as Yorigami have taken claim to the now ruined country.