As a girl named Harumi ends up sneaking into their school with her friends, she soon finds the faces of her friends have mysteriously vanished. When Harumi nearly drowns in a pool while trying to escape, she is rescued by a kappa named Kappaeru, who takes her to an underground base where she meets also meets the ice princess Yukiko and the fiery mage, Enma, who together form the Yōkai patrol, a group sent from hell to stop demons that appear on the surface. Determining the culprit is a face-eating demon, Harumi offers to lure out the demon so that Enma and co can attack it. Although Harumi…